My LO is now 12 weeks- appears to be gaining weight and peeing/pooping, but she is only taking 4-5 ounces a feed (6 feeds a day- one at 4-5 am, 7am, 10am, 1pm, 4pm, 7pm). She has been taking that amount for a few weeks now. appears satisfied... My DS1 was taking more like 7 ounces at this point. She was 3 weeks early and 6lb 10oz at birth, now about 11 lb 3 oz.