My girlfriend hit a rock that was at my moms house to stop people from parking in the grass. It was real ragged. It was on my old car, daily driver. She came in "I'm so sorry. I will pay to fix your car. Yada yada yada." I just got that disappointed look and went "It's okay." She goes "Can't you just yell at me and let me get it fixed? I don't like that disappointed look." I replied, disappointed again, "Don't worry about it." I knew her looking at it every day would make her realize she needs to be more careful, and that she owes me one. Hahahahahaha.
My advice to you, next time you are washing your car, go over that area real good so she sees you, and look disappointed. Open the hood, stare at it from the inside, thinking if you can pop it out. Hahahahaha.
Seriously though, you can probably get the paintless dent removal guys to fix it for about $40. You can still hold it against her because you "can still see that it's not 100% perfect."