Dd is two weeks old. She was back to birth weight at 10 days and has lots of dirty and wet diapers, so I think she's getting enough to eat.

She was taking an hour plus for each feeding, falling asleep quite a bit. Now she's taking a lot less time (about 20 min) and I can't tell if she's just more efficient or if she's not emptying the boob. She wants to eat pretty much all the time, usually two hours start to start. Sometimes she spits up after frequent feedings, like she's eating too much

So, I guess my question is-how do I know if she's actually emptying and getting the hind milk? Is it normal to eat that frequently if she's getting enough at each feeding?