Nutrition guidance while on stomach virus

Hello! My daughter is 7mo. We just started introducing solid foods and she is sick on a stomach virus. Her pediatrician saw her, but I got zero guidance on what/how to feed her while she’s sick. She doesn’t want to drink as much of her milk anymore.

Also, not sure what to do regarding giving her water. She does not know how to drink from 3 Sippy cups, and ends up all wet and I try giving her water of a regular glass. Do you have any tips?