The reason that I say this is that I know certain things that Elly loses sight of. The first thing that she lost sight of is that her mother only started treating her an adult competent to run her own affairs when she was in her late forties. Before that, Marian tended to act as if she'd had to come in and rescue her well-meaning but essentially incompetent little girl from a childhood scrape she'd gotten herself into. Always and ever, Marian smiled a big, friendly, innocent and stupid smile as she brainlessly destroyed Elly as an authority figure and left the poor woman holding the bag.
The second thing that Elly lost sight of is that Carrie Patterson also seemed to have spent her time seeing Elly not as a fellow mother but as that silly little girl who just can't take care of her son the way he deserves to. Again, we have a blank-brained old Anglo mindlessly undermining someone's authority and not coming within a kiloparsec of noticing the damage she did.
This is because of something everyone lost sight of except me: what a repulsive control freak John is. Carrie is too in love with his knavishness and Marian was too blasted flattered by the oily jackass to see what a dangerous person he is. He doesn't give a damn about how Elly feels as if she's taking a backseat to everyone in her own home just so long as he can keep her off balance and under his thumb.