She and her green conscience have been spurred to action by a plan by Tesco to build a superstore on part of a 28-acre site at Golden Hill in Henleaze, a pleasant, comfortably-off suburb of Bristol. She and up to 80 other local residents have spent 39 days in a round-the-clock vigil under lime trees threatened by the development.
Behind a wire fence, the Golden Hill Residents' Association and friends have built a temporary camp. On Wednesday, Mrs Evans and 60 other protesters were dragged away by 40 police. The protesters - including pensioners and mothers with toddlers - had linked arms or sat down in the muddy site entrance as a sheriff's officer tried to serve a repossession order won by Tesco in the High Court.
'I never thought in my wildest dreams that I'd one day be dragged away by police,' said Mrs Evans, 45. 'I'm a quiet person, I do things for my home and family. But sometimes you just have to take a stand, it's no good sitting at home. There is no need for another supermarket.'
Another woman said: 'I think it's outrageous that Tesco can reduce respectable people to this. Most of us have never been in trouble before.'
The protesters had lost a battle, but the war continues. Next day 50 people crept through hedges and set up a new camp beyond the gate. There they continue to sit, young mothers in jeans, older women in floral skirts, anoraks and sensible shoes. Other protesters included a GP and an accountant. Tesco is considering further legal action.
Planning permission for a supermarket was granted in the late Eighties by the then Secretary of State for the Environment, Nicholas Ridley, and Tesco bought the land in 1989. William Waldegrave, the local MP, agrees that permission might not have been granted under changes introduced since.
Nearly every car driving past sounds its horn in support. Protesters have taken their placards and leaflets to other Tesco stores in Bristol, and caused chaos by loading trolleys and then abandoning them at check-outs. There is a telephone list of volunteers willing to turn out day or night to swell the ranks at the sight of a bulldozer, and more than 2,000 protesters turned out to ring the site last month.
Every morning and evening they receive briefings from the man who has emerged as leader, Ian Martin, 37, a builder by trade and former chairman of the local branch of the Conservative Party. He takes legal advice from another resident, Brian Head, a criminal lawyer, and spends up to 18 hours a day on the campaign.
'The protest has gone on since 1987,' Mr Martin said. 'Tesco have known the depth of feeling against it all these years, but they now seem surprised we're fighting them.'
All the protesters mention the environment. Helen Hughes, 31, who joins the vigil before and after her work for a computer company and at lunchtimes, said: 'This is happening all over the country and if people are aware of the environmental issues, why isn't the Government? I can't bear the thought of driving past here and seeing concrete.'
Richard Rumbelow, a Tesco spokesman, said the company was determined to go ahead and had received many letters of support from elderly people who were pleased at the thought of having a supermarket near by. He said: 'The site has been derelict and vandalised since Bristol Grammar School sold it back in the 1980s. We purchased it after planning consent had been given. It wasn't us that inspired the planning application.'
He added that Tesco would landscape the development, which would one day include houses and a sports ground, and that more than 300 jobs would be created by the store. The company would be willing to look at an alternative site if Bristol city council suggested one - but it would have to come with a promise of speedy planning permission.
Back at the site, Alex Wallace-Dunlop, 20, an unemployed waitress, denied people wanted the store. 'People said we'd only be here a week and we'd be thrown off the site. But we're still here.'