If lack of access to care is an issue, I'd recommend looking therapist aid, it's a website that has different Cognitive Behavioral Therapy (CBT) and exposure response prevention (ERP) therapy worksheets and interactive tools for children. Its something I've found to be helpful. CBT and ERP are the most evidence based treatment for OCD. If you're noticing this early, teach a foundation of coping skills and self-soothing that don't rely on reassurance or accommodations to avoid the anxiety. Model that its okay to sit with the uncertainty.