She would be well advised to talk to 'Relate' the relationship guidance charity. ( used to be know as 'Marriage guidance')
They will be able to tell her where she stands from the legal point of view.
http://www.relategms.co.uk/
They help anyone, married, or not gay or straight. Once she knows what the legal position is she can try to come to an arrangement with her husband.
Some of the advice offered here so far is just plain wrong or years out of date!