It can be a sign of concussion, but other signs are drowsiness, confusion...you can probably safely google those symptoms without freaking out too much.

#1 fell out of his top bunk a while back and spewed about three times over the remainder of the night. If he'd spewed a fourth time we were going to do a hospital trip, but he felt fine in the morning, so we just took him to our GP who said he was fine. (Keep in mind, he could have fallen out of bed because he was feeling sick, so we aren't entirely sure what caused the vomiting.)

I'd watch for symptoms, and you know the usual - if in doubt, get her checked out. Hope she's okay. xo