If she only goes for real I would say take most of the money and put it aside so u can get her something gorgeous next time. With real jewlery, rather save up for something big and stunning then a few small things she wont appreciate.. and tell her with a card or something origional but make it personal and mushy. We like that too.
Cooking dinner is very sweet and tons of fun for her. She gets a night off and its a big gesture.