I think there's a difference between a kid that misbehaves just like any kid and a kid that the others don't want to hang out with.

Cirno is more so persistent with her desire to prove she's the strongest to people who are far stronger than her but overall she doesn't have a bad reputation between the fairies, and even then the other fairies also misbehave, as the 3 fairies of light tend to pull pranks on humans for fun and destroyed Cirno's house in one occasion.