My daughter was born on 17 May (2.9kg) and weighted 4.88kg after two months. She eats not more than 25oz per day, around 3-5oz each time, 5-6 times a day.
My boy drank about 22-24 oz a day when he was 2 months old. He is over 4 months now, drinks around 30-32 oz but he only weighs 15 lbs (50 percentile). Sometimes the weight is not in direct proportion to the milk consumption. My boy is a very active baby, waving hands and kicking all the time, maybe he used his energy that way…