Its too good to save some bitcoins for the children,but in my opinion as it transfer to wallet,we have ta recieve that money from wallet and then store in another bank account,because the bitcoin rate fluctuate day by day.
It is a nice thing to think about saving for the future of your childrens but as i am not considering my age to have a child well it will be a long time for me to do that so I might be storing all of the bitcoins I will gather in a wallet somehow and will be converting it into our currency so that it will not fluctuate anymore.