How would you handle it?

a friend at work step daughter is 10 yrs old and pulls lil pranks on ppl cuz shes bored or she thought it be fun, okay maybe a typical kid thing. but i think this one draws the line. she was at her aunts house and got bored and cut off all the whiskers on her aunts cats!!!!!! she doesnt know what to do cuz she is the "step mom", dad wants to be the good guy (real moms dumped them) and is a softie. we thought about having one of our cop friends come over and talk to her about animal cruelty....is that to harsh? what would you do?