What time is she eating supper? You might try giving her a small snack just before bedtime so she can brush her teeth then and you won't have to worry about that.

Another thing to consider is what you are serving for an evening meal.We sometimes forget that kids are growing and therefore need some "stick to the ribs" kind of food. You know how some foods make you feel like you'll never be hungry again, where 2 hrs after you've eaten others, you are starving? Just a thought. You might just watch what choices she makes from what you've served and see if she may be choosing "lighter" foods only.

As far as snacks, I read somewhere that if there is any food you eat without brushing your teeth afterward. . .that cheese would be less harmful to your teeth. Something to do with acidity best I remember.

I know you aren't giving your child chocolate milk at bedtime, but as a note of interest, I also read that chocolate milk is the absolute worst thing you can give a child in regards to tooth decay!