careful about vomiting her. I'm not a fan of that. You can dehydrate her that way.
Focus on not feeding the yeast. So nothing with sugar or carbs or acid in it for a few days. That rules out normal chicken feed, bread, rice, pasta, corn, potatoes, ACV etc. Egg (protein for energy) and live yoghurt is perfect. Though yoghurt is acidic it has good bacteria in which will really help. If that isn't enough, you can try crushing some probiotic tablets and giving to her.
I'm all for giving drugs when that is a quick fix and necessary, don't get me wrong, but lots of natural remedies work well in certain situations.
She has a yeast infection. That occurs when her body chemistry is out of balance. Work on putting that balance back right and the yeast will die. If you kill the yeast with chemicals, then it will return because you haven't addressed the perfect storm scenario where it came to thrive in the first place, if that makes sense. I mean, you can also do both: kill the yeast and make sure it doesn't have the right conditions to return.