Well, to be fair to Dickens, he did invent her, so I think his perspective is somewhat paramount. I agree that he wrote her character through the male gaze, and probably a good dose of misogyny. But the story of Miss Haversham, victim of the patriarchy, isn't a unique story or giving us any sort of new insight - we all know how women were treated in that era, before the Married Women's Property Act etc. All women were in the same boat, whether they grew up in happy homes or not. Any new angle on the background story would still lead to a miserable and completely self inflicted conclusion, rather than freedom, redemption, fighting the system or goodness coming out of misery.
She used Estella as a weapon against all men, and filled her head with cruelty. That's not giving her power. Giving her power would be giving her an education as good as any man could have and allowing her the freedom to be the mistress of her own destiny. Only if you equate feminism with hating men is her conduct vis a vis Estella feminist.
It might make an interesting documentary to look into the conditions of the time that produced the likes of Miss Haversham, but the actual character herself, with all that Dickens wrote about her, is, imo, stupid, pathetic and cruel. Not the makings of a good fiction series character.
I don't think Meghan (or Harry) probably know anything much about the. character or the surrounding history. They probably just thought, "Woman jilted, wronged by a man, that's a feminist story."