She's scared at what's happened to him, and she's also heartbroken that she wasn't there to stop it. If she could have stopped it, but of course she couldn't, and she knows that just as much as he does. Life did a number on this family, and regret lies like a veil over everything that happens between mother and son.

Yeah, there is a great deal of history between these two. I don't know if it'll shake out in any of the pieces I'm writing, but it was Zeke himself who gave me the seed of this backstory, when I watched the movie and realized that he didn't show any bitterness or anger when he mentioned his parents, just kind of amused resignation. That made me curious and interested me. When his mom showed up in that earlier piece, I realized they don't resent each other at all, but love each other in a sad, regretful kind of way. If only... seems to be their basic mood whenever they're together, and define their whole relationship.