bad news.....they will win in court
Yes the school will especially since this is in England and not here in the U.S.
Millais School, (Local education authority: West Sussex) is a Secondary School in Horsham, West Sussex, England. It is a Girls school of Non Denominational religion.
The court system there has been notably for the school authorities unless it is in a stituation were non-Christians are involved. The reason I posted this article on the school is that our judicial system has been following suit after other countries, especially England, in deciding just issues even though their laws are different from ours. No that isn't right either but it is indeed the case.