What to do, what to do...

This weekend we will only have one child in our house. Our older son is going on a camping trip with his scout troop. My wife celebrates a milestone birthday and turns 40 on Saturday. She has insisted that I not do anything to mark her birthday and I am trying hard to honor that. I do want to do something special for her but I am at a loss as to what. The woman doesn't wear jewelry and doesn't like excess things. She really only asks for stuff that she believes will benefit our family as a whole. I am stumped as to something I can get her or do for her that fits this bill. Any and all suggestions would be helpful. I have considered breakfast in bed but my wife wakes at the crack of dawn...