Is it odd, inappropriate or completely fine to contact a teacher (extra-curricular) to let them know the influence they had on your child? It wouldn’t be contacting them on social media, but through an organisation they now work for. Imagine it was music - (it’s not) - your child is now a professional classical musician, and this person taught them when they were at primary school. The teacher is unlikely to remember them, but in fact they had a huge influence. I can’t decide if it’s weird or if I’m overthinking it and a teacher might be pleased.