Brachot of children before an adult

A custom has sprung up in our family that after washing on Friday night, the young children (between the ages of 2 and 9) say Hamotzi before the man at whose house shabbos is at, says it. As the only frum person in the family, it at least is a good opportunity for the children of my siblings to get some religious input and be involved, but it does bother me that it creates a pause between the adult washing and then saying Hamotzi. My question is if this is actually a halachic problem or not? (My children also want to do this now when it is just us in the house, and for them it is practising brachot and actions they learn at the Yeshivah schoool they got. My kids are still young being 5 and 2)

I think, that for these ages it is tolerable, the pause is not a major issue as we in any case wait for all members to wash, this only delays the Brachah for just a bit more and has an important educational effect for the little ones. I would not though say it is the recommended custom, since one does the Brachah on behalf of all diners there is no Halachic need for a Brachah recited by every individual.