I would take her in to a vet immediately, perhaps a different vet for a second opinion. Animal hospitals, if there is one
in your area, are a good choice for
cats suffering from trauma. They tend to have large staffs that have seen a lot of this kind of thing. I recommend animal hospitals to a lot of people, but even more so for trauma cases. If nothing else, she will need antibiotics if she has an abcess and needs to see a vet for that.
I wish you all the best of luck.