Try putting some infant probiotic powder into her bottle. If you can't get infant, get an adult capsule and open it and put a few of the grains into her bottle or right onto her tongue and then feed her. It's been tested and works better than Gripe Water or Mylicon.
It made a big difference for my son. Babies are born with 'clean' stomachs, and don't have all that good intestinal flora that helps with digestion. Probiotics are the live culture that is in yogurt, and do a lot to help the baby's stomach have all the natural ingredients it needs to do well with digestion.