All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
A poor person is the one who has no wealth or not enough wealth to cover his needs and those of his dependents. If you offer money as an expiation instead of food, then you have to pay each poor person a sum that is equal in value to the cost of a lunch or dinner meal. Giving the expiation to children is not valid unless the children are poor and you pay the expiation to their guardians.
Allaah Knows best.