Don't Call Me Sister

When ML first left after summer it felt like I was reading I Dreamed a Dream
The mother gives off weird vibe! Why doesn't she want her daughters to be well-read? Right now it feels like she just wants them to be gullible and stupid so she can sell them off to anyone random.
I like that I can't guess who Merrick is, I don't want to know about truths the protagonists don't know.

Yes, they call her this like we would call people who likes sleeping, sleeping beauty, or white skinned short-dark-haired innocent animal hugger, snow white. There are more than one prince (cinderella original story) and there are PLENTY of servants in the mansion despite them being bankrupt. 

Can we get some clarification on what people mean with the MC abusing Cinderella?

MC is annoyed by Cinderella’s nievete and general helplessness, but there’s no sign of her being malicious.  She does try to look out for Cinderella at the ball and keep the creeps away from her.

MC doesn’t argue with her mom about taking Cinderella’s necklace, but that’s directly after it’s made clear that the MC doesn’t have any power to go against her mom until her birthday.  She cut the conversation off before her mom could get worked up into doing something petty to Cinderella.  And later she DOES get the necklace back for her, getting the other sis a similar necklace with a yellow gem so she wouldn’t make a fuss about the pink one.  So basically she’s just working more subtly rather than butting heads with her mom directly when it probably wouldn’t do any good.
If MC acts against stepsis in the future please tell me, as I’m just skimming the raws without being able to translate.

I kinda like that the MC isn’t a innocent, too good to be true heroine.  She’s enjoying the fruits of her mom’s gold digging, she’s got something of a harsh personality whose easily irritated by people, and she’s a little shallow with her love of fine clothes and being nobility.  But that doesn’t make her evil.  She’s concerned for both sisters, and she’s fully aware that her mother isn’t a good person.  It’s just that she seems to be focusing on subtly managing the woman and biding her time until she’s got the legal ability and power to go against her. 

That's my impression too, that she's the Duchess and also Javotte's mom by fake name, who is a witch. But we'll see after it's translated.

Also
Spoiler: manhwa ch 40Remember when I say "won't be surprised if Wishful will wake up with a kiss from her fiance later"? Well it really happened. But I'm not gonna say how because it's funny  

Well, the manhwa is still going. But at this point the raws, they are married and have 3 children I believe. 2 boys and 1 girl. The boys have white hair like their mother and the girl (she's the middle child from the way it looks) she looks just like her dad 

Lol the witch is Duchess Lilith who “shape-shifted” and pretended to be Javotte’s mom 

The ML IS NOT related to FL at all!
And here is the FL’s situation from the first chapter of the manhwa :

Spoiler: Fl in ch.1So FL’s was originally a daughter of a poor marchant, but after nearly one year of her father’s death, her mother remarried into the noble and wealthy family Winchester. And so FL and her biological sister became part of an aristocratic family. There they met their new father’s biological daughter, she was extremely beautiful but extremely naive too. So FL didn’t want to become sisters with a naive beauty, also she was named “Cinderella” for her stupidity, like FL wasn’t even related to the noble that her mom married but she was still the heir. Anyways at her 19th birthday someone gave her a poisoned apple that nearly killed her. And while she was in death bed, like in a coma, she heard how her mother didn’t attend to save her just because of the medical bill, while technically it’s FL who worked to have that money, and how her biological sister just faked her tears and said that they need to hold FL’s funeral lol.
The only one that really cared for FL and wanted to save her was Cinderella, and FL was really surprised by that. And so she want to have a husband that can protect her when she will fell ill like this time, and just won’t be “dead”.
so i think the novel is named “Don’t call me sister” because of the hypocrisy of her biological sis maybe? And that the novel is issued from the fairy tale “Cinderella” 

Is this novel relatively new? 

I was in mangadex right now and I found a webtoon with the same name

https://mangadex.org/title/63429/don-t-call-me-sister