From what I know, many babies cannot tolerate cow's milk and related dairy products prior to a year. I know in some areas, it's recommended to wait until at least 9 months and some suggest even a year to offer any of these - their digestive systems seem to cope better when a bit older.
I'd hold off on dairy for a few months, then try reintroducing. She might be okay when she's a bit older. If not, you can have a chat with her doc about it. Any dairy allergies in the family, BTW?