It's hard to rate this as it's basically two stories. The first is an interesting story (I'd give it an 8 or 9) about an abused woman forced to relive her horrible childhood and making the best out of it, taking her adult understanding of the situation to emotionally support and develop familial bonds that didn't happen the first time around. It's a story of love overcoming hate, compassion healing trauma, and finding family.
This story wraps up at chapter 33, and I think a lot of the high ratings for this series come from prior to this point. And when I say wraps up, I mean chapter 34 could have been an epilogue and it'd stand as a completed series.
I was really shocked to see it listed as Ongoing and that it was up to chapter 59. So I thought, hey, maybe with her future knowledge there's some big reveal or plot twist or other main event that the FL can take on and succeed at this time around now that she's solved the family issue with her brothers. Nope. This is literally an extended epilogue, set six years later, where the FL is now a Mary Sue and beloved by absolutely everybody in the kingdom. The conceit of the series is moot - the brothers adore her and treat her like a goddess now, and since she's a teenager the whole deal of her being mentally an adult is no longer odd, she just comes across as being a mature teenager. All the characters are one-dimensional caricatures that simple do and say the same things every time they appear. The only drama left is whether the FL will romantically get together with her engaged older stepbrother, which is gross (they grew up together as family from the time she was 7, and she's still only ~15-16 in this life while he's in his 20s, and the age difference might only be excused since she was originally 27, but he doesn't know that so ewww), but also intensely boring. There's nothing at stake at all. The FL has any number of genuinely good suitors, any of which would make her happy. She literally could be the next queen if she wanted to be. The older brother is stoic and reserved but lucked into an arranged marriage with a kind, generous, beautiful woman. He probably could come to love her if he could put aside his incestuous feelings for his adopted younger sister, but this is a story that seems to be on the side of getting the two of them together.
If you don't care about the gross incest elements I'd rate this part a 2, because it's still just an incredibly boring Mary Sue story with no stakes. If the incest bothers you, I'd give it a 1 and say absolutely don't read past 33. Just take the knowledge that everything turns out perfectly okay for everybody and it's like a smorgasbord of fairytale happy endings.