OMG are you serious?!?! If she had earmites, the vet should have known that immediately, they leave little black dots all insided the ear, and the yeast REEKS! That vet should really have known by smell and appearance that ears were the problem. And to put your poor baby through all the LS testing for no flipping reason, ugh!
IMHO, time for a new vet. I'm so glad that your baby will be okay, though, that's great news!!!!!!!!!!