The reason that I came up with that little scenario I’ve been hammering on is that by taking John out of the equation, something that has a severe negative impact on how Elly interacts with Mike and Lizzie would go away. It doesn’t matter if they got divorced or if Phil ended up having to dine on smug rat-bastard idiot to survive that doomed camping trip, having John go away would eradicate the feeling of being trapped that Elly feels. The desperation not felt because she had children before she was ready to be a mother is, of course, derived from her marrying a nerdy and entitled weakling with a need to tyrannize his family because dealing with the public makes the gutless, sunken-chested, witless douchenozzle feel like the man he’ll never be. Freeing Elly from having to ‘admit’ that she’s bullying him by insisting on being treated like a human being would allow her to have the breathing room to see that she shouldn’t be taking out her rage at being connected with a plum duff on their children.
As a for instance, she would have the peace of mind needed to see that her habit of shoving Mike aside whenever he wants attention is a piss-poor way to deal with the collapse of her hopes of returning to the university life that she never really wanted to live in the first place. She’d also be able to see that there’s a good God-damned reason her children try to get her to admit that she loves one child more than the other and always will: she acts the part because she can’t seem to find the time to play fair. Also, she’d notice that whenever she overhears Lizzie play Mommy and talk like a shrew, it’s not just her she’s quoting, it’s Marian. Figuring out that the mother she saw as a role model is an idiot who fears her would do a lot more for her than getting a diploma. It’d allow her to be an adult at long last.