How much should she be eating?

DD is 3 months old. For the past few weeks, she has been getting 5oz when she wakes up, then 4oz 4 hours later; 5 oz 3 hours later; 4oz 4 hours later; then 5oz about 3 hours later and that usually hold her for the night.

When we had her at the doctors the other day, I told him that her feedings are holding her for less and less time and I asked how much she should be getting and how often. He said that we can give her 5-6 ounces. Later in the visit, he said to add 1tsp of rice cereal to every 2oz that she gets to try to reduce her spitting up. Now I don't know if I'm supposed to be adding the rice in addition to increasing her feedings. I don't want to be start overfeeding her by adding the rice AND increasing her intake. The past 2 days, she starts crying about an hour before she is due to eat. I try to hold her off as long as I can but usually end up feeding her 1/2 hour earlier than she is "due". Then after she starts eating, she doesn't finish the bottle!! I'm so confused by what we should be doing for her. Does anybody have any suggestions?

Re: How much should she be eating?

I don't know much about the rice, but DS is almost 3 months also and eats 5.5 ounces every 3 - 3.5 hours. At night, he sleeps for 6-7 hours. He is on BM only. If he seems hungry b/f the 3 hours, we feed him.
Don't know if this helps.