By Phillip Kemp
BBC Money Programme
There are now more women millionaires aged between 18 and 44 than men, according to figures from the Inland Revenue.
The Money Programme decided to track some of them down to find out the secrets of their success.
Dawn Gibbins believes atmosphere is all in a successful firm
As a whole, it's estimated that women currently own 48% of the nation's personal wealth but this is predicted to rise to 60% by 2025.
Quick to take advantage of this trend has been Nicola Horlick, who earned the nickname "Superwoman" by balancing a top city job with the demands of a family of five children.
In November 2005, she launched Bramdiva, a financial advisory service targeted at women with assets of a million pounds or more.
She says women are now making it on their own terms in business, in a way that they couldn't when she first started working in the city in the 1980s.
"There was this tendency for women to try to emulate men. When you look back at film footage of businesswomen in the 1980s, they all had shoulder pads out to here and were dripping with gold jewellery. They all spoke in slightly deep voices and it was all quite scary."
Going it alone
There is now a record number of women directors sitting on the boards of the top FTSE 100 companies. Nevertheless, Nicola argues that the city still has a problem in more general terms when it comes to holding on to its female talent.
Nicola Horlick says the City still has a lot to learn about women
"Women don't necessarily want to stay at work. They might work until they're, say, 35 and then have a child and want to stay at home and by the time they return, they've slightly missed the career boat."
Increasingly these women are starting their own businesses instead, with around 700,000 female-run companies in Britain, bringing in a revenue of about £130bn.
Philip Beresford, who compiles the Sunday Times Rich List, says more and more of them are becoming millionaires as a result.
"The most significant area of growth is for women starting their own businesses. I would say that three-quarters of any rich list is people starting their businesses."
One of those leading the charge is former Veuve Clicquot Businesswoman of the Year, Dawn Gibbins, who owns the industrial flooring company, Flowcrete.
She considers herself on a mission to turn the traditionally male-dominated manufacturing industry from "grey to gold", by emphasising bright colours and using the eastern philosophy of Feng Shui in all the company's workspaces.
Dawn encourages teamwork amongst her staff through singing and by organising regular team events.
"You've got to make it colourful for a start," she says.
"Secondly you've got to make it a great atmosphere. The people that work here are wonderful. You've got to listen to the people."
This difference of approach is also felt in the way that women entrepreneurs manage their staff.
Judy Naake cut her teeth as an HGV driver
Laura Tenison - who founded JoJo Maman Bebe, a mail-order maternity-wear and babywear company in 1993 - is keen to foster the right image for herself amongst her workforce.
"I'm not being rude about men but I don't think a man thinks about it," she says. "A man would expect employees to respect him if he was driving a red Maserati. Whereas I would be embarrassed that my employees thought I was a rich bitch.'
Although most of her firm's customers are women, Laura is quick to defend herself from the charge that she instinctively leaned towards a female-friendly industry.
She cut her commercial teeth in the more masculine world of building, as the only woman working among 50 men.
Similarly, Judy Naake - who as managing director of St Tropez tan is worth an estimated £30m - cites driving an HGV when she was a beauty sales rep as good preparation for dealing with the sexism she was to encounter later on in business.
"I remember when I had my first delivery," she recalls. "The delivery man met with my then partner and he said, 'is this a job for the little women then? Does it keep her out of mischief?'"
Property is the basis for many women millionaires' success
One of the UK's richest women, Judith Wilson, worth more than £75m, argues that a more focused, female mind might even give others like her an advantage over their male counterparts.
With a portfolio of more than 650 properties, Judith's success has come from buying up almost exclusively two or three bedroom new-build houses in the Ashford area of Kent.
"I do know of other people and I'm afraid I'm talking of men, who have gone into business and made a success of it, probably become bored and gone into another business and then another one, and their whole core activity has gone out of the window," she says.
Judith is in good company, with nearly a fifth of the women making the Sunday Times Rich List last year attributing their fortune to some form of investment, often property.
Philip Beresford, the man responsible for compiling the annual ranking, has identified another trend, however, which may worry some of the married men on his list.
"Divorce is the hot new growth area for women making money," he says.
"In the last year we've seen half a dozen very big and very expensive divorce actions and given divorce rates in this country and given the accumulation of wealth overall by millionaires, I suspect this may be an even more lucrative area."
Sandra Davis, who worked on the big money divorce settlement between the Prince and Princess of Wales, says the case of White vs. White means that women can now usually expect to be awarded half of a couple's assets.
"I think that there is an investment opportunity in a short marriage," she says. "There has been no shortage of people getting a divorce."
One recent case that made the headlines was that of Mr and Mrs Miller, who split after just three years of marriage. In April 2005, Mrs Miller was awarded five million pounds by the High Court, equivalent to £5,000 a day. Mr Miller has since been given leave to appeal to the House of Lords against the decision.
But whether you make your million by breaking up with a rich husband or by starting your own business, Philip Beresford cautions that you may need more than you think to lead the millionaire lifestyle.
"To be super-rich in Britain, to be really rich where you don't need to work again and you can live off your investment income, you need £5-10m," he warns.
Filthy Rich and Female. BBC Two at 1900 UK time on Friday 27 January.