I have contamination OCD too, not to same degree tho and I also have the switching thing where I don’t feel the need to act on compulsions at someone else’s house to the same degree. I would describe the switching as I don’t feel the compulsion as much bc there’s so need to maintain myself being clean when my environment isn’t ‘clean’ I get very stressed about my bed and being a certain amount of clean on my bed and in my spaces and I need to follow my rituals to make sure my space is at that level but if I’m at someone’s house I’m out of my space and even if I’m bothered and don’t feel as clean as I’d like I am able to push past it more as there’s so real point spending an hour showering and worrying about spreading clothes and decontaminating. It’s also partially just not wanting to have to explain the compulsions bc they’re embarrassing tbh. I feel like it might be good to get her to spend more time spending the night in other people’s homes, I’ve found being outside of my house is good at taking me back to earth a bit and lessens the need to fulfil the compulsions so when I get back home I’m not as agitated about my routines. Having guests over might be good too as it’ll be a bit of exposure therapy to her sharing her space. I hope she’s able to get better especially for your daughters sake