Free spirit who had the PM's number

Mary Gladstone, daughter of the Liberal politician, justifies writing a biography of her mother, Catherine Gladstone, by saying "it was not so much a question of greatness as of unusualness, distinctiveness".

Sheila Goodie has set out to prove that Mary herself was unusual and distinctive enough to merit a biography.

Goodie has set herself a hard task. The biography is written in the shadow of greatness, that of a towering figure who was prime minister four times. William's career dictates the narrative as much as Mary's own life. Major events such as Home Rule and Egypt have significant space, but they are frustratingly never analysed, perhaps because they are recounted through the activities of a devoted and often uncritical daughter.

Nevertheless, Mary's commitment to politics had her spending hours in the ladies' gallery in Parliament.

Goodie argues that Mary is interesting because, unusually for a Victorian woman, she found herself at the centre of the action, ensconced in an office in Downing Street, a conduit to her father for many political players. Lord Acton describes his correspondence with her as "a way of conveying some things I cannot say right off". Goodie describes how Mary operated behind the scenes, using family ties to lobby on behalf of her father to open the way for the top job, and using political nous to smooth over quarrels. When she finally decided to marry at 39, she was torn at the thought of removing herself from the midst of public life, surrounded by influential people who courted her. Would Mary be as unusual a subject if she had not been in constant contact with figures from Arthur Balfour to John Ruskin and Lord Tennyson?

Mary's domestic life was that of a wealthy Victorian woman, and parts of the book provide solid social history. The Gladstone women come out well.

Mary was not the only independent female in her family; her mother did not conform to the norm of a Victorian first lady and spent much of her life undertaking philanthropic projects. Mary's sister Helen, through Mary's encouragement, became a don at Cambridge in 1877.

The biography can be read as a portrait of Mary as a woman of her times, but only to a point. Mary's activism was thin. There was a brief encounter with Josephine Butler, and Mary adored the "furious debates taking place in Cambridge on such matters as female suffrage, land nationalisation, vivisection and vaccination". Goodie argues, but cannot prove, Mary's influence with Gladstone on female equality, but at the same time Mary suggested a nepotistic appointment to the lady principal for Girton College.

For much of the book Mary's role is a traditional one. She was the only child in the family who could organise and deal with her parents. Roy Jenkins refers only fleetingly to Mary in his biography of Gladstone, as "her father's domestic secretary and the organiser of the household".

Goodie's work is rightly less dismissive of Mary, but it is hard not to see the family as the main space she occupied rather than politics.

Antonia Byatt is director, The Women's Library, London Metropolitan University.