Joyce Forbes looks after her grandson five days a week and campaigns for affordable housing. Susie Simpson absorbs the anger and pain of young men locked up in prison. Helen Harknett fights for social justice and LGBTI inclusion. At 92, Ann Gurney lives quietly these days.

The link between these four women is their membership of a growing band: female priests in the Church of England. Along with eight others, they feature in an exhibition of photographs, Here Am I, celebrating this year’s 25th anniversary of women’s ordination. It opens at London’s Oxo Gallery on Wednesday.

Facebook Twitter Pinterest Joyce Forbes: ‘Women bring something different to the priesthood.’ Photograph: Jim Grover

According to C of E statistics, there were 5,950 female priests in 2017 – a third of the total. Since 2015, 18 have been appointed bishops (out of a total of 114), including Sarah Mullally, who as bishop of London is the third most senior figure in the church. Last year more than half of those beginning training to become priests were women.

The exhibition, by the photographer Jim Grover, was commissioned by the bishop of Southwark, Christopher Chessun, to showcase the contribution female priests had made in the diocese, which stretches from the River Thames to Gatwick airport.

Facebook Twitter Pinterest Helen Harknett. Photograph: Jim Grover

“I had no idea what I was signing up to,” said Grover, hanging the last photographs a few hours before the exhibition’s opening. “It’s been very challenging, getting to know 12 individuals, gaining their trust, following them across south London. They are truly inspiring, committed, kind, truthful, compassionate people. It’s been a pleasure and a privilege.”

Facebook Twitter Pinterest Forbes in her robes. Photograph: Jim Grover

Grover’s photographs capture the extraordinary variety of a priest’s work: praying, preaching, ministering to the sick and dying, weddings, funerals, baptisms – the activities most people think of – but also moments of contemplation, clearing plates, comforting others, even cutting hair.

Facebook Twitter Pinterest Forbes as a baby. Photograph: Jim Grover

Forbes, 67, was ordained as an unpaid minister in 2004 when she was still working as a social worker. “By the time I was ordained, it felt very natural. I thought women priests were the norm, I didn’t realise then the struggle there had been. I wasn’t part of that journey,” she said. “Women bring something different to the priesthood. Women tend to listen more rather than jumping to conclusions. Sometimes you need to just wait before speaking or doing something.”

She came to the UK from Jamaica in 1965 at the age of 13, sent by her parents to live with an aunt in south London in order to get a better education, leaving behind six younger siblings. “I never really thought of myself as part of the Windrush generation then,” she said. Her biggest shock was not the cold, for which she was prepared, but blocks of flats, which she mistook for factories.

She said the revelations over the past year about the treatment and denial of rights to members of the Windrush generation had been “absolutely shocking. I can’t express how painful it is to me – and it hasn’t even happened to me.”

Forbes takes services at her church in Croydon on two Sundays a month, and fills in at other times when the vicar is away. She’s an active member of a citizen’s group campaigning for affordable housing, and she and her husband look after their youngest grandchild when his mother is at work. Although officially retired, she is as busy as ever, her energy going into “church, family and building a community”.

Facebook Twitter Pinterest Susie Simpson: ‘Female chaplains find that an open door.’ Photograph: Jim Grover

Simpson was ordained in 2000, and after eight years in traditional ministry she decided to become a prison chaplain. Grover photographed her in Isis prison for young offenders, next to Belmarsh prison. “If they are having a really bad time, they want their mum. Female chaplains find that an open door,” she told Grover.

Facebook Twitter Pinterest Simpson on a home visit Photograph: Jim Grover

It took seven years between speaking to her vicar – in a diocese where the bishop was not sympathetic to the idea of female priests – about the possibility of ordination and it actually happening. “I sometimes thought the only women who got through were persistent rather than holy,” she said.

Twenty-five years after the bruising battle over women’s ordination, a small number of C of E parishes – 4% – still opt out of having a female vicar or allowing women to preside at communion.

“There are still pockets of resistance,” said Grover, who returned to his faith a few years ago after a long absence and is now an active member of his church. “Some people just can’t accept. I can’t understand it, but I respect different views.”

Facebook Twitter Pinterest Dorothy Penniecooke, also from the Windrush generation. Photograph: Jim Grover

• Here Am I is at the Oxo Gallery on the South Bank in London until 2 June.