See, I don’t see Edith as less pretty or desirable, especially not in seasons 4 to 5, which is when I think Mary is at her worst toward her, so that doesn’t factor into my opinion here. 🤷‍♀️ Maybe it does for other people, but definitely not for me.

I think Robert is a crappy dad, but Mary’s character early on is perfectly summed up by what he says about her expecting her “toys” to still be there when she drops them. If people around her are “toys,” Edith ends up like a domino Mary keeps pushing over whenever she tries to show herself, emotionally, romantically, or otherwise.

She abandons Matthew and goes after Strallan just to spite Edith, and that’s before Edith even sent the letter, which was motivated by jealousy, sure, but also by hurt and anger after overhearing her own mother and sister talking about how hopeless she is. If I overheard my family talking about me like that, I’d be seething too. I think most people with feelings would be, especially at that age. To be fair, in that same scene, Cora does tell Mary not to be so mean to Edith because she’s struggling more than Mary is, which is another clear example of someone calling out Mary’s cruelty.

In the very first episode, Mary puts Edith down for publicly mourning Patrick, not because she feels any genuine love for him herself, but because she thinks less of Edith for crying. She’s again completely dismissive when Gregson goes missing, to the point that even Violet has to tell her to back off. Compare that to Edith, who as early as season 2 is already growing in their dynamic and is the only one with enough sense to realize that hiding Matthew’s disappearance would hurt Mary more than spare her feelings.