The child's portion is contained within the mother's portion, but the mother's portion is within the child's portion.
What I mean by that is this: when we go to a restaurant, I'm not about to spend $4 on a grilled cheese or waffle or whatever for her. Her little tummy is still only a few tablespoons big, so, ordering a full meal seems excessive. However, I do go out of my way to place my order in a way that I'll be able to feed her some of what I order. On a recent road trip, we stopped at a Bob Evans, and I ordered us a waffle and some fruit. She munched briefly on the cantaloupe, ate a quarter of the waffle, and I ate the rest. Later, we split a fruit and yogourt parfait at McDonald's. Her portion was from mine.
However, at home, her favourite foods are Annie's Homegrown Cheddar Bunnies, frozen waffles, and cheese. These things are, actually, pretty yummy. So, on occasion, when cleaning off her tray, my solution is, rather than to throw out perfectly good food or to store away 3 cheddar bunnies and a bite of string cheese, to just eat the thing. My snack comes out of hers.