Garters do a thing called false striking, which is probably what she was doing. Most garters will only bite as a last resort. Their natural instinct is to flee or hide when threatened or attacked...or to musk...or even play dead. If that doesn't work they will strike, but they usually do a false strike...which involves striking and just bumping you (or the predator) with their nose, without actually even opening their mouths to bite. It's a scare tactic. They usually only bite as a last resort...although some are quite nippy. You would know if she bit you. Although they are not venomous and do not have fangs, they do have teeth and it can hurt and can draw blood. Some members' garters bite a lot. And, some of the more aggressive species of garters bite a lot. I have never really been bitten...Cee Cee has nipped my fingers thinking they were food, but she didn't even draw blood...well, I think she may have gotten me and drawn blood on the side of my thumb once.