What Mary doesn't know can't hurt her. Besides she's seen how John and Sam get on and how Dean and Sam get along on good days and that's what stands out. She doesn't expect them to always get along either. Dean is more than good at getting Sam to eat something beside greens; Mary wouldn't be able to think of a time she saw Sam eat unhealthy if not for the fact that she pays attention to their bond. The boys grew up close just like she had hoped.

They have that common. Some days, all she has to cope with the whiplash of timeis the faces of her family and their stories. Today is one of the better ones. She could give him a run for his money in round one of an eating contest, but no one eats close to as much Dean does unless they're pregnant. (P.S. She ate way too much when pregnant with Dean). She doesn't fault him for not remembering; he was four at the time. "It's okay that you don't remember." She hopes that eases his mind despite the obvious way he wants to remember it. She'd be open to any questions he had about what was real.