Thanks for all the helpful responses.
Both the vet and farrier are firmly convinced it’s an abscess, and both of them are in agreement that x-rays would be a waste of time, money, and probably just put additional stress on her she doesn’t need right now. They are both of the opinion that we should just repeat the course of antibiotics and see how she’s doing in a few days, then go from there.
She’s already doing much better. She’s still sore, but it’s no longer non-weight bearing, and I even saw her trotting a bit yesterday, albeit with a limp. But she’s definitely walking much better, and putting a normal amount of weight on it. And she’s not pointing anymore either.
That said, once she’s walking normally, I probably will take her to the vet for x-rays. We have a lameness specialist about 35 miles away. Everyone I’ve talked to, including the farrier and vet are in agreement that it’s an abscess, and the fact that she is recovering so quickly tends to make be agree with them. (And it has been a very bad autumn for abscesses here because of horrible weather. The vet and farrier have told me they’ve seen a lot of them.) But since she’s had three since September in the same leg, I still want x-rays and I want the lameness specialist to take a look at her to rule out any underlying pathology that’s making it a recurring problem. Even if just for my own piece of mind.