Well that certainly evened the odds. She could take out just as many as he could, just as quickly, and with just as much accuracy. They were a hell of a lot closer to her, though. She managed to get about six of them before she had to shoulder her bow and go for the sword. It wasn't as easy, being human now, but it wasn't as life threatening as it had been moments ago. There were two people in existence she trusted her life to in a situation like this, Castiel and Robin.
(She trusted Dean, of course, but that was not quite the same thing. That was a ridiculous damsel in distress instinct that she couldn't seem to shake from before she got her memories back, and Dean being here would have been a terrible thing for her because she might have lost her ability to shoot. That boy gave her the most ridiculously complicated emotions.)
One of the hyena's caught her elbow, but she had it's throat open before it could get a good jaw-lock on her. By the time she'd fallen about four of them with her sword, she realized that was all there was, and her humanity seemed to come rushing back. Anna's sword clattered to the ground and she closed her fist around the gaping wound on her elbow. That was going to make taking care of her son more difficult... and, you know, other normal things people did with their arms.