How long has it been since you and your bride went on a picnic? Scout out a nice location, work out a menu, arrange for the kids if necessary, and spring it on her.
Bonus: Try an evening or night time picnic. The food can be more of a snack. A fire is great if you have a place to do that. If it’s cool, a blanket to wrap up in is a must. The dark and quite are great for talking or snuggling. Just don’t do anything she will feel up tight about!