Yeast infections can be common, unfortunately. What type of food is she on? If she is not in grain free, I would put her on a grain free food. Also watch the starches, like potatoes, several ingredients in the foods can " breed yeast". Add an omega 3 fatty acid, I use coconut oil for mine, they get it at night. In the AM they get sardine/ anchovy oil. Watch the treats as well. Many treats have wheat or other grains in them. I make my own treats using chickpea and coconut flour. Good luck.