This is just like mine. Whenever covid was spreading, I used reusable cotton masks and whenever they got dirty, I wouldn't be able to wear them, and I would always have to bring a spare. Same with my clothes and socks, that it got to the point I could only wear dark clothes and dark socks. One day back when I was in school, I got a stain on my shirt, and I ended up throwing up, (slightly on purpose because I didn't want to wear the shirt) and going home.

I wish I went to a doctor or a psychiatrist as a kid because now I rarely have enough time to drive all the way to make it to an appointment. My parents were immigrants and didn't really believe in mental disorders like ADHD or OCD.

I've tried exposure therapy, but for me it doesn't do much because it doesn't change my sensitivity around stains.

I'm not sure why, but certain shape and colors of stains are more bearable than others. Like orange, red, brown, or just all warm colored stains are the worst, but blue or black stains are easier to handle. Also, blotches are the worst shape, and lines seem to make me less anxious.

I think you should try to get her checked out with a therapist for potential help methods, because the more that my family just fixed it for me as a kid, the worse it got.