Sucking vs. Eating?

Blue789

My girl is kind of a lazy eater. She tends to fall asleep, which I know is normal. But she also sucks to self soothe and I have a hard time telling when she's eating vs. when she's sucking. She normally does 15-20 min per side, which is about 1.5 oz (thats what I can pump in that time). She'll fuss periodically and give hunger signs after the "normal" time and if I let her continue to feed/suck, feeding sessions can last 90-120 minutes.....she can't be eating that whole time, right?

How do you tell the difference between actual eating and sucking to soothe?

 Also, we've tried pacis, but she didn't latch very well afterwards.