D.S.
My five month old son started food at four months. His current eating pattern is: Breakfast - 2Tbls cereal, 1 jar fruit & 6oz bottle, Lunch - 2 Tbls cereal, 1 jar veggie & 6oz bottle (sometimes I skip the cereal and do 1 fruit and 1 veggie with the bottle), If he is hungry between lunch and dinner I give him a 6oz bottle, Dinner - 2Tbls cereal, 1 jar veggie & 6oz bottle. He's in bed at 8:00 and doesn't eat again until he gets up in the morning...usually between 6:00 and 7:00. We're getting ready to start meats. My Ped. said by six months he should be on three meals a day. So far so good and my baby boy is happy with it. I know all docs are different so I just thought I'd let you know it's okay to start food if you're ready!
When we were doing only bottles Ped's rule was to never stop feeding just because the bottle was empty...let your baby stop because she's full. So I'd make an 8 oz bottle and let her stop when she's done.
Good Luck!