My son repeated 3rd grade for similar reasons (except he was not the youngest in his class) & now he has just started his first year of high school (he is 14, year 7 in Australia) we can really see that decision has paid off. We involved him in the decision right from the start & were guided by him-it would’ve been impossible if he wasn’t on board or feeling like he had no say. We weighed up all the pros & cons together, slept on it for a while & then he decided he was happy to repeat. He didn’t have many good friends in his year level when he was in grade 3, and that didn’t change much when he was repeating, but he was happier in himself. His slow processing speed had meant that he had missed large amounts of information in class & there were large skills gaps emerging in his reading and writing. He had a good IQ so it was frustrating to see him struggle to keep up & repeating gave him a chance to consolidate all those skills he had “missed” by not being able to focus or process.
At the end of that year, we changed schools to a school that made more accommodations for kids with ADHD & ASD. Socially he began to improve but when he began Ritalin (on the advice of his teacher-we were reluctant before then) we had a new boy who started to catch up in the areas he struggled with academically and he had made a really good friend. At the age of 13 he announced that he was “now interested in people” & has finally started to apply all those social skills he had learnt about in theory with conscious effort! Academically, he has evened out and is no longer just the kid who is only good at math, but he his doing well in all his subjects. Most importantly, he is confident, has a handful friends of lovely friends, he doesn’t get bullied & he loves school.
Every single child is different, but for our son the combination of repeating 3rd grade, changing schools & starting meds really worked. I wish you both all the very best.