3 month old threw up once today?

My exclusively fed baby threw up A LOT in one episode this evening. She hardly ever spits up & has never thrown up like this before, so this was very unusual for her. She was preTty upset after & screaming & she finally calmed down when put at the and fell asleep. She didn't eat more than usual before & she's been fine all day, & I didn't eat anything today that was out of the ordinary. It was a little hot today so I don't know if the heat affected her? & I know my husband was bouncing her a little harder than usual cause she was fussy and he was trying to play with her to calm her down. So I don 't know if it was just a little too rough on her? My question is that ok for her to have thrown up once or do you think there could be something wrong with her? & do I need to rehydrate her with water or electrolyte solution or something that the store sells or is she fine?