The age of mining is dead for solo miners for almost a decade now. If you're looking for ways to amass bitcoin for your child, it's best to just buy it on a regular schedule. This applies the principle of DCA (dollar cost averaging), so even if you buy it high on 1 month but bought it very low on 2 months, it will find a nice average for your entry price.

Or instead of wanting to teach your child to trade at an early age, why not do it yourself, earn some money, and send your child to a good school then teach him/her the principles of trading when he's/she's knowledgeable enough. Most parents fail in teaching their kids because they are eager to have them learn something they're not intended to learn at a very early age, without considering what the child wants to learn at that point. Making them interested in bitcoin by seeing you do it first-hand is way better than forcing them to learn it just because it gave you the means to survive in this world.

Teaching them something about crypto is great, but let the kid enjoy his/her life as a kid first, and just inspire him/her by doing what you do best in front of him/her.