This is because, of course, she doesn't especially want to see herself as the author of her own misfortune. It won't be that her fear of taking her children to airports that expose her to terrible people who call her a negligent dumbass or her default refusal to understand that other cars will be on the highway that cause the delay that exasperates other people, it'll be on John for willing traffic into existence, the kids for worshiping chaos and Georgia for kowtowing to someone who isn't actually getting married. Similarly, it won't be her blank-witted inability to understand how weddings work that cause people to call her a moron who flips the bird to social norms out of pea-brained immaturity and narcissism, it'll be on the mothers of the world who want to punish their daughters for wanting to be people in their own right.
This leads us to a reminder that it's a good thing Jim's ill health took her mind off of the angry whispers from people who looked at her funny for not planning Liz's wedding like she was supposed to. Did she WANT to go through life as an anonymous drone who didn't see herself as being part of her children's lives and did she not want anything in return for her sacrifice? What the Hell is wrong with this woman and why are they supposed to deal with her being a malfunctioning idiot?