Plenty of wet nappies?
Slow weight gain aside (and it does slow down a fair bit from 12 weeks or so) the other signs seem alright. The pulling off/crying could be an age thing - DS had some issues around this age. He was becoming more aware and didn't want to be stuck at the breast when there were interesting things around to look at.
Where do you feed her? Nice, quiet, darkened room might help. Is she better feeding overnight than during the day?