It's powerplaying because... Well. It's an auto-hit! It's certainly not severe, but
she decides that your character's pinned. She doesn't give you a chance to object or avoid it; she decides what happens to your character-- not you, as it should be. No one should control you character except you! In fighting roleplays, it's best just to write the attack ("
leaps at the fox") or the attack and a possible outcome ("
leaps at the fox and tries to pin") to let the other player choose what happens to their character.

Tossing an 'attempts' in there would've remedied it, though!
god modding
It's a term used in rps that is used when someone does an action/actions that are impossible to defend against. It is also used when someone describes how the other person is affected by it, thus leaving the player unable to rp his/her own character.
Edit: Oops-- Nathan worded it better than me!
