I think it needs pointing out that this report is more than a little one sided.
The school does allow muslim girls to wear traditional dress, if they wish. The arguement has infact been specifically over the jilbab. The school itself has bent over backwards over the years to accomodate the religious needs of it pupils.
http://news.bbc.co.uk/1/hi/education/4832072.stm
Ironically, the clothing she has decided to wear outside the court would in fact be permissable in the school. So quite why she needed to wear a jilbab in school, but is quite happy to not wear it outside of it is beyond me.