It would be one thing if she were merely another houseproud woman who fears being thought poorly of by other houseproud women because she doesn't live up to an arbitrary standard. What seems to be going on is that while she wants to live in a house with other people, she doesn't actually seem to want to be reminded of their presence. This need to want to have her cake and eat it too seems to be why Elly had the unpleasant habit of waiting until her children were distracted and just shoving stuff into bags to be tossed away in the misguided belief that it would not be missed. Her reasoning seems to be that since her children don't clean to her standards on their own initiative despite her attempts to include them, she once again has to do what they're too selfish and lazy to do. Besides, since they never seem to remember what she wants them to remember, it only stands to reason that they ain't gonna miss what she throws away especially since they didn't take care of it.
What Elly doesn't want to admit to herself is that most of why the kids keep their room a mess is because they see things quite differently. They don't see a victim being backed into a corner by mean, selfish lazy children who hate her and want to torment her because they love chaos. They see an unyielding, humorless rock of malice and aggression who doesn't want them to have a childhood because she's evil and loves TYRANNY and hates fun and childhood and thinks she knows everything ever. Her favorite act of malice is swooping down at random and clawing through their belongings at random intervals because smiles and laughter and happiness are like Kryptonite to her. The reason that they don't tidy up is that they know that Horrible Gaping MAAAAAAAAAAAAAAAAAA!!!!!! will huff and puff about how they're not doing it right, whine her whine about a dagger in her heart and stuff things in bags without knowing or caring about what she's doing anyway.
What makes this as annoying as all Hell is that Elly can turn around and say that Marian was out of line to do the same damned thing to her for the same damned reason. Elly does know right from wrong, it seems. It simply seems to be that she can't admit to being wrong.