Well they are definitely playing camera tricks because she has a different knife right before and after this scene. Here is what I was talking about.
I can't tell what it is. Looks like res c though.
Yeah , the handle looks bigger in the pic after she stabs zombie, thought that was a bit strange, at first I thought it was an Yard Elmax blade, or a war dog, but in the second shot the butt looks way to large
