It is  a good idea to make investment on btc for your children as by the time the grow up the investment will be 100 -10k fold greater in value so it is not a bad idea to keep some investment on btc for your kids.And i have already kept some like that for my future.As per what i know about btc the value of btc will continue to grow as it is becoming more and more popular and hence there will be increase in the demand and the market will never go too low like other form of investments nor have to wait for longer period of time to get profit.