I would go back to the vet. I had a dog do that once and she tore some ligaments. It sounds like soft tissue damage and the best thing right now is total crate rest. Even if there is nothing torn if she is still favoring it she needs rest. I have performance dogs and see soft tissue injuries all the time. As much as it sucks she should be confined to a crate for at least 10 days. That means on leash to go potty and back in a crate. no stairs, no jumping, no running, or any other activity. If you feel bad about confinment, I just take them out on leash and let them lay on the couch with me. But I will not let them jump up or down on the couch, I lift them.
I say still check with the vet and make sure it's nothing more serious. Good luck