And by chips, you mean french fries, right?? and jacket potato, would be baked potato???? Just so there is no confusion and people think potato chips..

and do not know what a jacket potato is. As Bicker says, it is a fixed price for the meal, I would hate to see her pay that for just fries or a baked potato.
I would think they would try to accommodate you but maybe you could call the restaurant and ask?? If not, before you get there, maybe do it when you get there by just having guest services at your resort call. Hopefully, for that kind of money, they might have something that she would like to eat. If not, and you want a happy wedding dinner, I would suggest another restaurant.