That x-ray is cool!
Ok, not bashing your vet, as they can't know everything about every animal, but you need a culture done to know which anitibiotic (or combination) to use. Each one treats a different RI.
My advice, get a culture done and/or get F10 and a fogger. You could treat her with the F10 while you are waiting for the culture to come back. I've treated a gravid female with F10 and the eggs came out fine, she bred/laid again the next year. I've treated with injections, F10, and a combination of the two. F10 works quicker and better IMO. When I've treated with injections it has taken 3+ weeks till they looked cured, then another week or two on top of that. When I've treated with F10 they looked amazing by the end of the week, then I treated for one more week after that and it didn't come back.
I was totally against F10 since it's a cleaning product, but I'll stand by it now that I've tried it.