Of everything she expected to come across or to be attacked by, Mabel definitely was caught off guard by the bat, eyes widening and managing to duck just in time. Barely. Luckily she was short enough that his swing missed her head by mere inches, and if it were anything but a human attacking her, Mabel would have certainly fired by now. But it had been awhile since she had any human contact, and she was more forgiving than that.
However, she wasn't going to allow whoever the stranger was to get away with almost bashing her brains in either, punching him roughly in the stomach. While not a zombie, she had no intention of blindly trusting him, especially without knowing whether he was assaulting her by accident or intention of robbing her. If they were going to talk to rectify the situation, it would only be after she subdued him.