For breastfed babies, the nutrition in the breast milk changes throughout the nursing experience. These changes happen gradually over time. The infant formulas are designed to meet the nutritional needs of most babies during the first year. In the second year, most kids do better with a drink that isn't quite so rich. The fat content and calorie content can go down, and toddler formulas are designed to do that.
It's okay to continue the infant formula, as long as it's not too many calories for your baby. Formula will provide most of her nutritional needs while she is experimenting with solid food. It's okay for her to eat as much or as little as she wants in the way of solids. It will vary day by day. To encourage solids, offer them at least three times a day, preferably before a bottle.
For most kids, it's best not to coax them to eat with moving the spoon like an airplane or with music or sound effects. They have an internal mechanism that tells them how much to eat that you want to keep intact. If you suspect it is not intact or there are serious food allergies complicating the picture, then it is usually best to work with a feeding specialist to learn how to encourage feeding while still keeping the child's motivation strong.
She may be fine with 16 ounces of formula a day now. Or she may want 21 ounces -- whatever she seems to prefer in that range. At the one-year physical, you'll get to see on the charts just how she is growing.
All content here, including advice from doctors and other health professionals, should be considered as opinion only. Always seek the direct advice of your own doctor in connection with any questions or issues you may have regarding your own health or the health of others.