She might have caught a bug of some type could be a side effect from something you did took a medication a imbalance or something i think if it doesn't go away get checked by a dr.
could be a side effect from something she took could be sick it could be the weather if its really hot or cold if it doesn't go away i would see the dr does she take any meds.
Low blood sugar, caught a bug, fever, dehydrated, started a new medication or took too much of it, too hot/ heat exhaustion. A lot of different factors can cause dizziness.
