Diaper rash

Brittany • Mommy to a wonderful 12yr old boy, 9yr old boy 7yr old girl 6yr old girl and 3yr old girl. Due March 11th 2023 with a boy.
My daughter had a bad rash and I took her to the doctors. He said it looked like a yeast infection and it took 3 different prescriptions to work. I also switched from regular diapers to organic diapers doctor recommended. Every time I get the rash cleared up she goes to her dads and comes back completely red. She hadn't seen her dad in 6days. She went there for 4hrs yesterday and is so red. I've told him he needs to use the organic diapers cuz her skin doesn't like the chlorinated diapers. But nope she comes back in Luvs. I honestly think she just sits in piss at his house. I'm so irritated and there's nothing I can do about it and that drives me so crazy.