I only remember a specific situation in the novel. The protagonist was reincarnated as a princess (or nobility, maybe even just into a wealthy family?) and she didn't try to hide her maturity. Her father relied on her a lot and her brother looked up to her. This caused her mother to suffer because they looked to the mc first and not her. People would praise the mother for raising such a good daughter, but the mother felt that she grew up without any input from her. At one point she had an outburst of anger saying that she "hated" her daughter that the mc overheard. It was resolved when the mc said to her mother that although she taught herself to read and many other things, her mother was the one who taught her basically everything that had nothing to do with her previous life. I don't actually remember anything about the actual plot-line. I think the mc was using the skills her mother taught her to make a bunch of connections to try and do...something important to the plot that I don't remember. I think she mentioned that she wasn't actually very social, but was able to do so well because of her mother. I feel like I wrote a lot, yet didn't give much information...Thanks in advance for any help I get!
... not a novel, but i read this and immediately thought of a naruto fanfiction that seems to fit the bill? welcome to tomorrow by izaranna on ff.net. (i'd link, but i've never posted before, so.) the main character is reincarnated as the oldest uchiha child. she's favored by fugaku and well-loved. in chapter 10, she overhears mikoto venting to kushina that she wished that that child (the mc) had never been born, and in chapter 11 we hear more about mikoto's grievances and the extent to which she feels that her authority has been suborned by her daughter. the mc was trying to form connections so that she could try to prevent deaths.
Omg thanks so much! I knew it might have been a fanfiction, but I have been reading nothing but web novels for a while and had no idea what fandom it could have been in. Just remembering these vague ideas was bothering me so much. Again, thanks for your help!