Dub! Material components
Maybe preschool has been a while for some of you. I can see exactly why the teacher and parents were concerned.
The material components for the spell in question include a bit of fur and a rod fashioned from amber, crystal or glass. Amber and crystal are expensive, and crystal and glass are both potentially dangerous on a preschool playground. Where did she get the fur, praytell? I picture a class hamster with a bald spot.
Secondly, when you've got a preschool-aged child, that child is probably peeking, cuteness-wise, and you're just not ready for them to grow up. Third level arcane spells?! That's graduate-level thaumatergy, for crying out loud! I'd be a little saddened too.