You're doing perfectly! I would focus on baby and sufficient output. Babies feed based on their genetics too. My ds come out at 3.5 kg which is average but at 2 is the size of a 4 year old (no exaggeration). Little wonder he fed 2 hourly as a tiny baby and doubled his birth weight so quickly. Dd was the same weight at birth and was a less frequent feeder and is a more average size (she was a big spewer though too).

Follow her cues and just try to keep feeds within a four hour period until you are sure she is gaining weight and your supply is settled a bit. It will be different in a week and then two weeks. You are not going to interrupt a good sleeping pattern or anything at this age because she doesn't even know day from night yet. Just keep doing what you're doing!!!