Turns out she had osteosarcoma and is now in doggie heaven as of this past Thursday. Keep looking around for her.
Oh, and....I forgot to mention, keep up her pain relief until you are pretty certain she doesn't need it (bright-looking, eating well, wagging, no shivering or shaking, no unusual lethargy)
And of course, watch her for any change of symptoms, any swelling, or anything else you don't like the look of. Get her to the vet if you see any worsening of her condition.
Well this is going to be very sad for her and she won't like it, but my advice is that she will have to have strict rest. For at least 2 weeks!
If this is a badly-pulled muscle or tendon injury, with strict rest it may start to heal. If it is something like this, you will be able to see if there is any improvement. If there IS no improvement after thoroughly resting that leg, then she will need to go back to the vet I'm afraid, because there could possibly be something more serious going on. And she will need tests of one kind or another, and of course they do come at a price....it isn't easy.
So start the rest-therapy right now. Unfortunately that will mean something like cage-rest, and will involve you and your family giving her a lot of attention one way or another, bringing her food, changing her water, being regular with her "bathroom-breaks"...and very importantly, giving her anything at all to prevent her getting depressed while confined. That might mean singing her songs, even reading aloud to her (yes I know it sounds silly, but people gving her attention while she's caged-up will help to keep depression away)...scratching her ears, massaging her muscles, anything.
When she goes out, that is STRICTLY to pee and poop, and she must do that on a short leash preferably with someone holding it who is strong enough to control her movements and won't allow her to lunge or pull.
It's not going to be easy. And it's going to be hard on her. But I think you have to try that. I do hope this rest will help, and it is nothing more than a bad sprain. But if she doesn't get better, she will need the vet again.