When we were going through the process of trying to determine if my daughter can have milk or not, her pediatrician was fine with her just drinking water for a bit. I wouldn't worry too much at this point anyway.
Try some coconut water too!
Milk can make you phlegmy, so if she's had congestion and or cough, that might be why she's not doing okay with milk
Could be teething?
Maybe her taste buds are still off from being sick. She can get calcium from yogurts and cheese instead. Milk isn’t necessary.