As a concerned mother of a 12-year-old facing anxiety and religious OCD, I am wondering if my daughter had the right Niyyah but made mistakes in Wudu without realizing it, are her past Wudu and prayers valid? Should we encourage her to ignore her doubts?
Bismihi ta'āla
Indeed, you must be concerned, and if not stopped, it will consume her, and make her life miserable, and everyone around her as well.
She must only follow her shar'i takleef. Nothing more, nothing less. Her duty is to constantly dismiss her doubts, and consider whatever she does as correct, even if other thoughts enter her mind, and even if she continues to think she did it wrong. She ignores it.
Once she does this for a while, it will, in shaa Allah, break the cycle of her intrusive thoughts.
And Allah knows best.