Have you tried changing the position you feed her in? A couple of things that helped Max were holding him so he was upright and facing me, or lying down next to him on the bed to feed. He swallowed less air that way.
I also found with all my children that they each had specific positions they liked to be held in to burp after a feed, and if I didn't burp them enough then they had bad tummy pains afterwards.
Experiment with different holds and see if different sorts of tummy pressure help her work out the pain.

Kerrie