Pretty much shoot in the chest as see runs at you. Remember, she hears where you are so if you stand still and have your teammates move to the right or left of you, you can shoot the chest as she runs at them or you. Just dodge at the right moment if she
is near you. If you go down, have a friend lure her away and your other friend pick you up. It took me two tries but in the end. It took 10 reloads with chainsaw to take her down, and I was by myself with AI's.