Like Stacy said, formula or breastmilk need to be her main sources of nutrition for several more months. Her formula intake should remain around 32 oz until at least 6 mo, then it can drop a bit to 26-32 oz. As for dropping feeds, it's up to you and her how many feeds she gets, as long as she's still getting enough formula. When we started Tyler on solids, he was on a 4 hr routine at 6 mo, so he got 4 feeds during the day, a dreamfeed, and was still waking at night. We weaned the night feeds first (not an issue in your case) then the dreamfeed, and he stayed on 4 feeds a day until he turned 1 and we introduced whole milk.
Hope that answers your questions!