The girl, in her late teens, was interested in exploring Christianity before she was placed with the foster carer. But when the girl decided she wanted to be baptised, council officials said her carer had failed in her duty to preserve the girl's religion and should have used her influence to prevent the baptism from going ahead.
They said the girl should stay away from church for six months, and later struck the carer off the fostering register. The carer, who has over ten years experience looking after more than 80 children, is now challenging the local authority's decision. Her case is being backed by The Christian Institute's legal defence fund.
The carer is a practising Christian, and made it clear to the girl when she arrived that she could continue to practice her Muslim faith if she wanted to. In assessments before the baptism, the authorities said the girl's emotional needs were being met, and noted that the carer was showing understanding and respect for the girl's culture.
The carer's lawyers say there was no evidence that the change in the girl's religion would harm her, and argue that the authorities failed to listen to the girl's views.
The carer, an Anglican who attends a local evangelical church, said: 'I did initially try to discourage her. I offered her alternatives. I offered to find places for her to practise her own religion. I offered to take her to friends or family. But she said to me from the word go, 'I am interested and I want to come.' She sort of burst in.'
The carer said that the girl's social workers were fully aware that she was going to church and had not raised any objections. The girl had told her auxiliary social worker of her plans to convert before she was baptised in January last year, and the social worker had appeared to give her consent.
The Christian Institute's Mike Judge said: 'All people should be free to change or modify their religious beliefs. That surely must be a core human right in any free society.
'I cannot imagine that an atheist foster carer would be struck off if a Christian child in her care stopped believing in God. This is the sort of double standard which Christians are facing in modern Britain.
'In recent months we have seen grandparents, a nurse, adoption agencies, firemen, registrars, elderly care homes - and now a foster carer - being punished because of the Christian beliefs they hold. It has to stop.'
The carer's solicitor Nigel Priestley said: 'There is no doubt that the event that provoked the council was the decision by the girl to be baptised.
'This girl was 16 and has the right to make this choice, so for the council to react in this way is totally disproportionate. Even at this late hour, we hope that the council will resolve the issue.'
A council spokesman said: 'From the details provided, we believe that this information relates to a child who is the subject of a final care order in favour of the council. In those circumstances, we are unable to pass any comment.' [Christian Institute]