Solids shouldn't actually replace the bottle until whole milk is introduced at 1 yr. Until then, your best bet for determinind the ratio of food to bottle is to track her formula intake. Formula should be her main source of nutrition until you introduce whole milk, so the amount of solids you offer depends on how her formula intake is doing. The guidelines I use are:
6 mo - 32 oz
7 mo - 30-32 oz
8 mo- 29-32 oz
9 mo - 26-32 oz
10 mo - 24-32 oz
11 mo - 24-32 oz
Different sources have different guidelines, but this is what I used. And every baby is different, so some may take more or less formula than that, and that's perfectly fine. Does that make sense?