Pre nups are a thing uk thing tho not legally binding, however judges will take them into account when deciding how assets should be split (ive been advised by two solicitors in my family to get one before i marry my fiance). A judge will throw them out if the circumstances have changed to a great amount, signed too close to the wedding, or if provisions for children haven't been madePre-nups aren't a thing in UK law so she'd have to split everything.
Isn't her family religious too? I imagine there could be pressure to not divorce - or if she/Mike are still religious themselves they might be dealing with those conflicting feelings.