The chances are you won't have heard of Britain's richest woman: Kirsty Bertarelli is worth £7.4bn – money that came from her husband's family's pharmaceutical company, and now comes from property investments. The next woman on the latest Sunday Times Rich List is Charlene de Carvalho, whose £5.49bn comes from her father's Heineken brewing fortune. After that is Kirsten Rausing, who owes her £3.9bn to her father's Tetra Pak business; Tina Green's £3.3bn comes from her husband Philip Green's Arcadia empire.

You see the trend here? You have to get to number eight in the list – Dame Mary Perkins, founder of Specsavers – before you find a woman who didn't amass her fortune through marriage or inheritance. But she only comes 84 in the overall list (and she shares her £870m fortune with her co-founder husband).

So the record number of women in the list – 108 compared with 105 last year – is hardly a feminist triumph. Five women are included following divorces from rich husbands – including Slavica Ecclestone (£740m) and Irina Abramovic (£155m) – there are no men who make the list because they divorced rich wives – and there are three lottery winners.

There is an encouraging number of women who are not judged by wealthy husbands or male relatives, including Xiuli Hawken, a Chinese-born property speculator married to a British teacher, who is worth £819m, and Amanda Staveley, who heads a private equity firm. "It is nice to see women who have made their own wealth rather than inherited or married it," says Karen Gill, co-founder of Everywoman, a network to support women entrepreneurs. But why aren't there more? She points out that the people who top the list tend to have made their money from male-dominated sectors, such as industry, oil, pharmaceuticals, property and construction. "There is still a challenge for women to get doors open, break the ceiling and have confidence."

Where women have done well, she points out, are in the retail sector – for example, Linda Bennett, who started LK Bennett shoes, and Chrissie Rucker, whose White Company sells bed linen – and those in the creative industries; writers JK Rowling and Barbara Taylor Bradford have amassed £560m and £188m respectively.

The other issue, says Gill, is that the UK "is not overly predisposed to enterprise. If you look at the list, you have to get to number seven before you find someone of British descent." (And he is the Duke of Westminster, not exactly a self-made billionaire.) If women were more encouraged to set up businesses, she states, it would add £60bn to the economy. "In the UK, just 15% of businesses are started by women, but in the US it is about half and half." She says she is optimistic about the future, when the Rich List in five or 10 years' time may reflect the success of more female entrepreneurs, but for now it seems the main avenues to millions is still to marry a rich man – or divorce him.