(let's just say the girl dressed in all black with her hair up is how Nina fights but only with her bare hands and not a pool table stick)

Nina: Now where the hell are you killer

Before she went around the corner she saw cops

Nina: Damn it these guys are everywhere

Nina had to wait them out so she can continue her look for the killer once she realized that they weren't leaving she decided to go back to the library through the back way. Once she got there something bad was about to happen. Once she got back a fight went down so she went to get in the middle of it.

Nina: Hey, hey knock it off

Then out of nowhere someone hit her so she got angry and began to fight just like Sam and Dean taught her how to and like her dad did. Then the cops came in and stopped the fight between the people.