This is to be as soon after they attain the use of reason as possible. The first Communion must follow sufficient instruction and sacramental confession. Therefore in our country it is usually delayed until the teens.
Confirmation is a rite of passage, marking the entry into spiritual adulthood.
So it is sensible to delay it for these few years. But Eucharist is food and drink for the soul, so it should be given to children as early as they can realize that it is truly Jesus they are receiving.