Lilla has had thrush for about a month now

She's been on nystatin but it's just not cutting it. Is there anything else I can try? I've heard about Genetian Violet, but does it really work? Where can I get it? None of my other kids have ever had thrush (I've never even had a yeast infection ~ knock on wood LOL), so I am really at a loss here.
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Cory
Mama to Takoda, Sagan, Eiley, and Lilla
Eiley in a gorgeous set made by craftykitty
Shhhh, I kept the kids out of school so we could go hiking at the lake