Bed wetter at 17!?!?! H E L P!

My sister doesn't have is app so I am posting for her. For about a week and few days now my sister has been saying that her vagina is irritated. At first she thought it was an allergic reaction to soap but then more symptoms started to show up and she guessed it was either a UTI or Yeast Infection. Our mother took her to the doctor and tested her for UTI and it turns out negative he says it is probably a yeast infection and promoted her to drink a lot of acidic drinks. She hadn't really been drinking any but her symptoms got better but not completely over with. Now she is starting to wet the bed and has a lot of urgent pee moments. What do you guys think HELP?!?!?!