Ancient China setting. Possible wattpad story, most likely not finished translation/story. In her past life, she forced her husband to marry her and turned herself into typical villainess when her husband fell in love and married with another woman. She died drinking the poison she prepared for the other woman but her son knew/thinks that it was her suicide/last effort to gain her husband's attention. Not sure about the husband response to it but when later, he asked the son to be the Crown Prince/heir due to his righteousness, perfect scholar countenance etc, the son declined as to follow his mother's wish: to live peacefully, as her grandmother wished for her (but she married the husband and died full of regret). When she was reborn, she decided to avoid the husband and mourned the lost of her beloved son (since she will not marry the husband again). Yet, it was when she was grieving for the son that the husband (most likely the ML) got curious about her and was interested in her (as opposed to disgusted by her in the past life).
The specific scene that I remembered was the son and husband conversation after her death: Her name was meaningful, as her family wished her to live peacefully. Even though she's evil, she raised the son righteously and told him to never be like her. The son might have implied that she had chosen to die that night, instead of poisoning his father's new wife. But he wasn't angry at the father, just telling him that his mother might not be as evil as people says she was. The son refused the title of Crown Prince/heir because more than anything, she wished for her son to live peacefully like she should have.
I like this genre (female MC, rebirth--or even transmigration, ancient times/China), but I have never heard of this story. I hope you find it, and if you do could you please share?
the rebirth of the evil consort by etysukaisih from wattpad, i think ・ ᴥ ・ (i still cant post links sorry ヽ༼ຈل͜ຈ༽ノ)
Since I can post links: https://www.wattpad.com/story/129533060-the-rebirth-of-the-evil-consort Is it this one?