Bitcoin's a good store of value, But I don't think relying on it for your child's future is a good thing, although it could be argued. Personally, I'd invest it into something else with passive guaranteed growth instead of bitcoin's which is cyclical in nature. Or perhaps make use of both bitcoin and a trust fund at the same time. That way I can gusrantee and maximize growth of my son's money through bitcoin's volatile upshoot in prices every now and then, and make sure the money stays valuable especially when I pass away.
I have had children, and I have thought about this in the past, instead of creating a savings account in the bank for our children's future, bitcoin would be a better option in terms of profit. But with bitcoin's volatility and bitcoin's future uncertain, placing our children's future in bitcoin is quite risky.
We often say that bitcoin investments should only be used with money we can lose, but this is our children's money, and we cannot lose it. So I will also choose a safer option than bitcoin for my children's future.
You don't need to completely avoid bitcoin investment, though. You can invest part of the money for your child in fiat and other part in bitcoin. If bitcoin loses price by the time your child grows up, you won't lose the entire money, rather only a minor amount that shouldn't affect his future at all.
On the other hand, if bitcoin rises a lot yet, as most enthusiasts predict, this can be a life changing for him.