I don't know what kind of liquids you are trying, but stay away from dairy at this point. I would offer water, 7-up, pedialyte, things like that.
Also, sometimes they will tolerate popsicles at this time rather than standard liquids.... a bit of liquid coming down from a popsicle sometimes stays in the tummy better than actually drinking liquids.
Do you know how to tell if she is getting dehydrated? That is the big concern with tummy bugs....
http://www.babycenter.com/0_dehydration_11407.bc
This link has symptoms of dehydration, and suggestions, also.