Looks like a brindle pit bull to me, but I admit that nearly any mix of pit bull can look like one...or act like one.
One of two things probably happened. Either the two dogs started fighting and she got in the middle, or, she fell and uttered a scream or high pitched squeal. This most likely happens when a dog/dogs consider the human as an equal instead of their Master.
The nose looks too long for a Pit to me but a lot of Pits are crossed with something else. The dog in this picture looks just like the Catahoula Leopard hound/Rotty cross I had. Everybody thought both of mine were Pitt’s too but they weren’t even close. A couple of cyclists were riding past my house once and my dogs were running along the fence. One guy said, “Is that a Pit Bull?” The other guy said “if that’s a Pit it’s the biggest da*n Pit I ever saw”. Catahoula’s are big, brindle and spotted but the head is a little different than a Pit.
I saw something once that had several pictures of what most people call Pit Bulls and said to pick out the Pit. Only one was a Pit. I’m not saying they aren’t Pits, I’m just suspecting that they aren’t.
Plott Hound? The brindle coat and muzzle look like a Plott. Plotts were/are bred in Carolina’s to be bear hunters. Never heard of one attacking a human though.