Together with Siobhan, a social work lecturer and the third trustee, they have the legal responsibility of determining how the charity will spend its money.
Although the concept of the private charitable trust is long established (many thousands of people, from prosperous Elizabethan merchants to Cliff Richard, have trusts bearing their name), the Women's Trust Fund has extended the idea, creating a mechanism through which a group of friends combine their giving and decide collectively whom to help.
Their charity makes small grants of up to pounds 500 to women's groups and to individual women. Their aim, they say, is to help women develop skills in health and education. Recent recipients include women's aid and rape crisis centres and women struggling to make ends meet on training courses.
'We get letters from women who have had children and are stuck financially, but have a real drive to do something with their lives,' Nina says.
The WTF began informally in 1984, when Anna (at their request, the women's names have been changed) inherited family money. 'I got a lump sum, quite a large amount, and I decided at that time that I wanted to give away about a third of it. I had a lot of good women friends who became part of a small collective, making the decisions together,' she says.
Nina, who joined a few years later, is in a similar position to Anna. 'I don't want to go around playing Father Christmas. Giving as part of a group is more neutral; you don't feel you are riding your own whims so much. It also nudges me into taking action,' she says.
From the beginning the group has included women with money and those without. 'It's been important to work through the feelings of guilt in having a lot more money than our friends,' Anna says.
In 1989 the group decided to become registered as a charity. Nina describes their process of becoming registered as 'very tortuous', but says that this was mainly because of ignorance.
'We wrote to the Charity Commission in London, and after about six months they replied saying that we should talk to the Liverpool office,' she says. 'We also spent a lot of time talking to a solicitor in Manchester.'
Eventually registration was approved, though Nina feels that the form of wording in their charity deed, which speaks of relief of mental or physical distress among women, is unnecessarily Victorian in tone.
Setting up your own charity has become simpler since last year, when the Charity Commission produced a series of model constitutions, including a trust deed. Also included in a free starter pack is a comprehensive (and now compulsory) questionnaire, which potential new charities must complete. 'This means that we are presented with the information we need,' a Charity Commission spokesman said. There is currently no charge for registration.
'There are a lot of private charitable trusts. People like the idea of greater involvement in their giving,' says Lindsey Driscoll, legal adviser at the National Council for Voluntary Organisations.
She points out, however, that the charitable aims need to be worded with care. By law, there are four charitable objects: the relief of poverty, the advancement of education, the advancement of religion or the benefit of the community (a tightly defined category). 'Not every good cause can be a charity,' Ms Driscoll adds.
Becoming a charity has meant that the Women's Trust Fund has been unable to make overtly political gifts. It has, however, been able to benefit from the generous tax relief (via Gift Aid) on the donations made to it by the women. In addition, capital passed to a charitable trust is exempt from capital gains and inheritance tax liabilities.
Anna says that the WTF has pounds 33,000 invested, managed by Giles Chitty of the ethical investment managers Barchester Insurance and Investment. It gives away about 7 per cent of the funds each year, though the women are considering distributing more of the capital in the future.
WTF, PO Box 1, Rossendale, Lancs BB4 5AB.