I spy another one. Guess it wasn't just Mike and Chris.
When I was really little I would secretly go into my closet (it was a big closet) and write stuff all over the walls in red crayon. Nobody ever found it until years later, when I moved to the room downstairs.
You've captured well the lamentations of a childhood expired. The image you present is haunting... an old house where children once grew up, now all gone, and a woman longingly gazing at their walls, and seeing old crayon marks, even if they're not there (I take it she's looking in and remembering it differently than it is, not literally seeing crayon marks).
Very cool stuff, PDV.
Facts do not cease to exist because they are ignored.