Hi Grace, hope my popping up here doesn't bother you - just read this apropos the "other" thread.
Not sure whether you'd consider me a fully sane and well-adjusted person, (you decide!), but I would certainly say that I've had a happy and successful life overall - so far, (40+ atm).
However, between the ages of c.7-11yrs, I had what would certainly be diagnosed as OCD nowadays. Because I was an only child and then had a much younger sibling, I was able to keep nearly all my rituals and mantras secret. I remember being made to feel very awkward about my constant handwashing, but nothing else was ever exposed. I spent an inordinate amount of time on my own, though.
Looking back, my parents were going through a tough time - I think they almost split up on several occasions - my mother had several miscarriages and my sibling was born handicapped. I changed schools a lot.
Gradually, things must have improved because the OCD more or less disappeared. Now and again, if I'm really stressed, it may pop up briefly, but not to any debilitating extent.
Hope this helps. It's great that your dd has caring, understanding and supportive parents who have the time and patience to help her through this. Good luck.