Yeast infection or ?

Me and my girlfriend have been together for 3 years now and have not once had a yeast infection. Then one day she said that her was hurting, then it hurt to pee. She did have some gunky colored discharch but wasnt sure it was a yeast infection. we went to the nearest drug store and bought a test. The results said that it could be a yeast infection or it could be normal. I bought the overnight medication. The next day i took a look at it for myself and there were a few little white spots on the inside of her lips. after the medication fully drained i took another look. the white stuff on the sores were gone but still had little holes left behind. I could only think of two ways it could be a yeast infection. ONE we tried out a new lubricant. TWO her mom just had a yeast infection and they took a bath the same day in the same tub. She went to urgent care and the doctor told her that it could be but wasnt sure. he took a swab test and said it would be five days.Does this sound like or a yeast infection gone bad?