For BV and yeast infections try filling gel capsules with Boric Acid and doing a nightly suppository. It's an over the counter option that has worked for generations of vulvas. Switch to every third night after the problem clears to keep things on a level ph and no sex on that night.

It's pretty surprising to me that no one has suggested that she is possibly being reinfected by her partner, especially since she mentioned this problem started when they stopped using condoms. It's unusual for a male partner to carry BV,but not impossible, especially if they happen to be uncircumcised. I don't know if there were details in the letter explaining this that got left out, but if there weren't, that's a lot of crappy gynecologists.