I would strongly advise against trying to get your case processed and interview in Yangon. I have a close friend who has been trying to get his Burmese girlfriend here. They have been waiting for an interview for over a year. In his words “the US embassy in Myanmar is a shitshow.”
That said, as she is a citizen of that country, I believe she must interview at that embassy. I could be wrong, but I imagine my friend would have looked into interviewing in Thailand or elsewhere given his circumstances. Good luck.
