if you can't be kind, be quiet. If only people remember that in the "HEAT" of the moment. When we were young, we were told just about the same thing. "If you can't say anything nice, don't say anything at all"
Givers have to set limits. Children begin life as takers. Adults give, and set limits to respect their needs and the child's. Children will learn to be givers as they grow, from the adults that give to them.