My DD is around the same age and I am regulating how much solids she gets for that same reason. I think that three meals a day by nine months is fine, as long as those meals are small enough that she still eats bottles. Also, I believe by nine months they are down to three bottles a day, roughly. That's also why it is so important to make good food choices that also provide what formula used to. Such as meats for iron & protein, cheeses & yogurt for calcium (and you can add goodies like wheat germ, flax oil and other things to give a calorie and fat boost to these), and lots of veggies, fruits, nuts and seeds.
