I don't read LNs because I expect them to be perfectly written tomes full of high literature, but even then, it's rare to find a work which manages to stumble into so, so many unforced errors at once as this one.
For starters, it somehow manages to combine three of the most tired tropes of three different LN genres - the "technically weak but actually super strong" of fantasy, the "technically just a commoner but there's a crowd of devoted nobles and officials willing to use their power for my benefit" of historical novels, and the "technically a loving man who's so possessive he's hostile to any other man in the vicinity of his daughter/sister/other relative/fiancée/wife" of romance.
Then there's the writing style, which has it's share of peculiarities, like attempting to add a mystery by omiting from the reader information obvious to everybody present (like names of characters or any hints of their status or identity) in a way which makes it painfully obvious what is being omited, thus paradoxically robbing it of any mystery.
There's characters exhibiting curious behaviours, like people with all the powers of royalty at their disposal who, over the course of several years, couldn't find a way to deliver a message saying "sorry fam, can't see you right now because of reasons", making for a completely unnecessary drama.
There's bringing up huge plot developments and then completely resolving them in the same scene, before the reader even manages to find a reason to care. Notably, there's a several pages long scene of unnamed and previously unmentioned nobles being arrested for previously unmentioned crimes against previously barely mentioned characters...
And it just piles on and on. And overall, the book totally undermines itself by trying to have a cake and eat it too, in many different ways. Is the protagonist's abusive home a thing nothing could be done about, or is she close friends with people who could apply so much pressure even on a noble? Is she a target for bullies because of her weakness, or obvious prodigy? Is she mild-mannered, or always ready to apply violence? Somehow, it's all of the above and more.
And finally, the less said about Yui's adoptive father intending to take her out on regular dates, the better.
I made it through a third of the book and just couldn't find the strength to go on.
