This is something on my mind latley. For starters I would teach my child that magick is very real. Maybe around 5-8 teach them simple magickal concepts or myths from around the world. I would tell my child what I did privately. But I would wait to introduce left handed path and proper workings until they were properly a teenager.
For example theirs a ritual where you take the first nail clippings of your child and bury them under an ash tree and they will from then on be gifted with a beautiful singing voice. I would probably do that ritual and teach my child about it around age 5, though tell about it younger, itās a ritual that canāt really harm them in any way but gives them a gift [song] via magick, itās an easy folk magick ritual to perform and would be a great teaching lesson as they get older. little things like that to ease them into it. tell them about my operations at an arms length/distance but only truly start teaching them when they develop an interest should they proper. Of course never forcing a child is rather important. If your child rejects magick, respect that and donāt be one of those people.