How much nursing after solids?

Courtney
My girl's been eating solids for about a month now. She eats cereal for breakfast, usually a fruit for lunch, and a veggie for dinner. I've noticed she's nursing less now, obviously because she's getting more from solids, but I'm wondering how often is normal? She's just over 7 months and we're usually nursing 6-7 times a day. I just don't want my supply to drop since my mil (childcare) is still giving her 15 oz of breastmilk while I'm at work. It's hard enough to keep up with that, I'd hate for it to get worse!