The quick code buttons seem to be broken for at least a few people on this forum. You insert a picture by uploading it onto another site (imgur, for example) and then writing out [ img ]insertpicturelinkhere[ /img ] without the spaces between the square brackets and the image codes.
However, even with photos we can't diagnose your pup. Your vet should be happy to discuss options for you, and be willing to do diagnostics to figure out if you're dealing with an infection, allergy, or something else, as well as a medication that will work best for her. I couldn't tell if the problem was largely with her anus or her vulva, but it sounds like the vet has diagnosed her with a recessed vulva (also known as a hypoplastic vulva). This condition does greatly increase the chances of yeast and urinary tract infections, as well as other issues, so ask your vet if you need to be considering surgical correction (esp. if she's already spayed).
However, even with photos we can't diagnose your pup. Your vet should be happy to discuss options for you, and be willing to do diagnostics to figure out if you're dealing with an infection, allergy, or something else, as well as a medication that will work best for her. I couldn't tell if the problem was largely with her anus or her vulva, but it sounds like the vet has diagnosed her with a recessed vulva (also known as a hypoplastic vulva). This condition does greatly increase the chances of yeast and urinary tract infections, as well as other issues, so ask your vet if you need to be considering surgical correction (esp. if she's already spayed).