She was definitely not infected by lycanthropy at the battle. As others have said, it was not a full moon and she was not bitten.
Carole gave her scars on her back and neck. I gave her a badly scarred abdomen.
In my stories (she appears in Tales of the Battle, MIT, Bare, Moon, Moons and in the background of most of my other stories) she is a werewolf, but I have yet to complete the part of her story. My Lavender was seriously injured and wheelchair bound until she found the (drastic) cure.
My recollection is that Bill was clawed, not bitten, and that because Lycanthropy is a curse they are "curse scars" whether they are bite or claw marks. I'm not certain why Carole differentiates between the two.