Having fun in your 20s, rearing a family in your 30s or getting wise in your 60s - at what age do women feel most fulfilled? Kate Gibbs talks to Yumi Stynes and others about the best years of their lives.

Yumi Stynes, 35, refuses to dye her hair. She confesses she's lied about her age in the past, "partly a female thing and partly a vanity thing", but will not budge on the tell-tale long grey streak running through her almost black hair. "This shows I am a warrior! This is an indication of the life I have lived, of the scars I have acquired. Why would I deny myself those symbols? I am proud of who I am and what I have done."

These are the words of a person who is profoundly glad to be right in the middle of her 30s, still youthful but not young. Stynes says she is happy in health, happiness, home and work. "The whole thing feels like it's coming together."

A presenter on morning show The Circle and television channel Max, Stynes might well feel that everything "just clicks" - but how real is this my-life-is-just-perfect-right-now thing, and do all women reach it at the same time, if ever?

Is that perfect moment in our lives - when the dark clouds peel back and we find love, happiness and success and are at our absolute best - to be found in our past, present or future?

If Stynes seems incredibly content with where she is right now, she says it's because, for the first time, she is taking responsibility for who she is. Turning 30 forced a sharp U-turn in the way she addressed problems, and the things she had agonised over in her 20s were suddenly within her control. "There was a real psychic shift around the age of 30, when I started taking more responsibility for myself. I thought, 'I'm not going to whinge about the fact that I'm fat, I'm going to go to the gym. I'm not going to complain about my career, I'm going to see what I can do that I really enjoy.'"

A feeling of potential arrived with the realisation that she could overhaul her own life: "There is longevity to the idea that you can improve things, but it has to start with you." Stynes had felt stymied in her younger years, partly because she was in a relationship with the father of her two daughters, now aged nine and six, where she felt there was no potential. "As soon as I got out of that relationship, when I was about 32, I suddenly felt my whole world open up. I no longer had him to blame for feeling shit. I took responsibility and suddenly there was hope and optimism."

Daily exercise now gives her stability in her mind and confidence in her body. "When I'm 40, I hope I don't gallop head first into middle age. I've seen it in friends. It's like they want to spread, they want a fat gut and to dress in fisherman's pants. I think that is a choice. You can be that doughy, passive, TV-watching, junk-food-eating person, or you can choose not to be."

Just as Stynes suddenly felt potential when she moved into a new life stage and attitude in her 30s, for another strong Australian woman a sense of complete balance also arrived at a major turning point in her life, but much later on.

Australian Living Treasure and cookbook author Margaret Fulton, 86, is sure about the moment when absolute calm arrived and everything changed. "It was just after the monthlies finished, and I had learnt a lot about life. I suddenly reached a point when I had the advantage of knowing what life was about, but still felt that I hadn't lost my youth."

With a career spanning more than 60 years, Fulton says that what has most boosted her happiness index is doing something important, rather than gaining acceptance from others. "Showing women at home how to truss a chicken or do something interesting with lamb empowered them," she says. "And in doing so it made me proud."

After two divorces and scores of cookbooks, there was a wonderful moment of balance in Fulton's life when her adult daughter was happy and everything was calm and good. She realised that she'd had a good life, but there was still lots more ahead. Having something to look forward to, feeling potential in your life even at 86, is essential, says Fulton. She does regular yoga, works with Greenpeace, and is planning a trip to Scotland to visit family next year.

"It doesn't matter how pretty or gloriously leggy you look if you've got nothing to look forward to," says Fulton. "The trick is always planning for great things in your life. And if it doesn't happen, so what! You'll probably find something better anyway."

"Growing old is not a lot of fun," says Margaret Pomeranz, 66, Australian film critic and co-host on the ABC's At the Movies. But she accepts it with the confidence and sense of self that being older bring. Pomeranz was involved in a bad car accident when she was young, and now her frame "is the one thing that is letting me down", but she still finds consolation in aesthetic things - "in beautiful clothes, a wonderful art form".

For Pomeranz, "part of the growth thing" was the realisation that material items do not matter, and that friends and family are the only things that make you really happy. "When I was in my 20s, I felt that having a really good time every waking moment was really important. I think you get perspective on that."

Having children also changed everything, says Pomeranz. "Reality comes in with a heavy thud when you have children. It pounds any sense of selfishness out of you." This also brings a certain satisfaction. "It's a matter of putting one foot in front of the other and finding joy in the moments that you can find joy in."

It is her children who inspired what Pomeranz remembers as the ultimate happy moment in her life. "I had a lunch for Mother's Day up the coast. There was a group of us, with all our children in their late teens and early 20s. They were funny and enjoyable. We walked along the beach and we swam, it was bliss.

Everybody was happy and generous and smiling. I don't think it gets any better than that."

Age may bring an older body, but it also lets you grow out of seeing yourself the way you think others see you. "You start seeing yourself though your own eyes. For me, that has been really important, especially in my industry." For someone who always wanted to get wiser as she got older, Pomeranz now realises that if you do get wiser, you just wish it had happened a lot earlier.

Nicole Trunfio, a model from Western Australia who has worked for design houses including Chanel, Dolce & Gabbana, Versace, Christian Dior and Gucci, has just turned 25. "I've never been happier, and that has everything to do with the fact that I finally feel like a woman now."

She attributes her often complicated relationships with friends, family and "especially boyfriends" in her teens and early 20s to the uncomfortable shackles of youth and insecurity. "Some of the biggest life lessons happen between 16 and 24. It's a hard time. It's when you need your friends around, but these are the people who are going to give you the worst advice you'll probably ever receive! My advice to young people is to support your friends, but get advice from older people."

Trunfio holds up the saying that "a woman's beauty is worth more than a man's money", but fervently argues that beauty is something that grows with time. Using 35-year-old model Megan Gale as a source of inspiration, she says older women have taught her that ageing is not necessarily a downward spiral. "I don't know what tomorrow holds, but if I keep a positive outlook today and tomorrow, and be positive about the human condition and what makes me feel good, I know that promotes inner beauty."

Fashion designer, cookbook author and new mother Fleur Wood, 37, has built a career in an industry in which what a person is like on the outside is important to success. But after 15 years entrenched in a world in which beauty is seemingly skin deep, Wood says she's become an expert on what makes a woman truly beautiful. "I have seen women who wear incredible designer clothes lack any kind of beauty," she says. "It's not about where you shop or what your skin is like. It's about being yourself and having your own sense of style and grace. Margaret Pomeranz is a perfect example of that kind of beauty."

It was when she shrugged off "the outside" altogether in her early 20s that Wood found herself in a state of "pure contentment". Living in the Indian Himalayas and meditating, practising yoga and designing clothing ranges for a cultural-preservation project of the Tibetan government-in-exile, she developed a sense of who she was. "I was incredibly fulfilled then. I didn't care whether I was beautiful or what I was wearing. I think happiness came from being of service to other people."

Since then, Wood has rarely felt such a strong sense of being at her absolute best - until she recently gave birth to her first child after trying to fall pregnant for two years. In her new role as a mother, she feels a sense of greater meaning and selflessness, being completely dedicated to the needs of someone else.

Wood balances out her often stressful career with regular exercise and meditation, plus visits to the kinesiologist and chiropractor and other "health freak" commitments. "There are studies that say people with spiritual beliefs are more happy than those without. I believe that is true."

As a successful 46-year-old, Network Ten senior news presenter Sandra Sully realises now she can have it all - but never all at once. "That extra phrase 'at once' is the clincher," she says.

There are stages in life when you're more happy, when you can roll with the punches a little easier, says Sully. But she pins these stages on certain people and events, and says she can't think of a period in her life when every element has completely clicked at the same time. But then, why should it? "There is no section of your life that is quarantined," she says. "You may have found love or feel very healthy, and some things gain more importance at different stages of your life. But I can't hang my hat on, 'My job is great, I've never been happier', or, 'I'm in love, I've never felt better'. I'm alive and I'm where I'm at through tumult and adversity.

"Balance is a catchphrase that is unfair to women," adds Sully. "I hate the pressure women feel, that they have to be in love, be beautiful, have a family and a career. We're fighting too many battles just to be perceived as successful."

For Sully, as a younger woman there was a naivety about the idea of being in her prime. "One of the great things about getting older is that you know yourself, especially if you're happy with the person you're becoming." It's the ideals forced upon us by others that makes us feel unbalanced, she argues. For men that's the pressure to provide, and for women it's the pressure to have a career, babies and, of course, beauty.

"Nirvana, if there is such a place," says Sully, "is where you feel good about who you turned out to be, and I don't think there's an age limit on that."

This article was published in Sunday Life magazine on 9 May 2011.