I think that it comes down to "you know your baby best." Hate to be SO general and not helpful, but really, my own experience is that it can be more than one thing. Work closely with your health providers (health visitor if you are in UK, or GP, paed, etc) and if you feel that it is getting too much to handle and that it just doesn't "seem right" then push them to not brush you off (if that is what they are doing).
I got the "every baby possets, don't worry" for months. DS was puking up entire breastfeeds mid-feed, all over me. On formula, he was doing what you are describing. We were told he was crying from hunger so feed him more. Then my HV went down the reflux route, but GP refused to believe it was problematic, said he would outgrow it at 14 weeks.
FFWD to 17 weeks and DS was finally diagnosed with milk intolerance, as that is what the puking up was from all along.
Now, the thing is, I don't want to say "oh that sounds like milk allergy/intolerance" because it could be that your LO is a very happy spitter and it's nothing. Or it could be reflux. Or, it could be a problem with milk. But, there are a few different things that it COULD be and I would say it's best to keep notes, take pictures, watch her poops as well, and keep pestering your/her doctor if you don't feel that it's getting any better.
Hope that's not too vague or unhelpful . . . ?