Hi Cindy ,
It's nothing I experienced, and is actually the opposite of your problem, and the problem most experience. At least she won't get bloating! Has she called her surgeon's office to see what they say.
I have read that forcing burps can be possibly damaging to a wrap, and that healing patients should avoid burping on purpose. I only read that on one surgeon's post-Nissen recommendation, but it's worth checking in to.
Obviously her stomach has been through a lot and producing gas is a byproduct. Is she avoiding all the gas-producing things like straws, chewing with her mouth open, talking while eating, gassy foods?
I'd definitely recommend she check with her surgeon regarding the issue. I haven't really heard of excessive burping...maybe someone else here has. As I said, at least she doesn't have the dreaded bloating!
Hope you're having a good day!