Ok so— the mc was reincarnated or transmigrated into a baby. I think she knew or guess the troupe of the world she was in. Anyways,,, as a kid she was obsessed with magic and becoming a mage. But the wizard of the kingdom (and a seer) denied her of ever being his student and she just became dull after that. She was married off to a Duke(pretty sure the ML), and I think on her first night the prince showed up and slept in the same bed as her on accident. She gave the guards a punishment by letting the strongest knight hug them. BUT this Duke had like another girl he brought with him to a party, mc thought they want to be together but can’t and was using her as a cover. But actually the girl(let’s just call her ‘the knight’)was just a person from another world and wanted to go back home(?) and was a training partner with the duke and the prince. The knight meets this person who had a crush on the duke and basically just wasted her whole life on and was like ‘ I like her’ because of her abnormal strength. (Im pretty sure this girl smashed a table and threw a Boulder somewhere in this manhwa) they way they meet was that she ran past the knight really fast and just wanted to know who this women was. I remember in this manhwa that the mc and the knight sit down and talk. Mc wants to know if the knight was from Korea but turns out she’s from an entirely different world. ps the knight was like in a sect and had a master n everything. I hope my essay of what I remember helps X,D I can’t remember for the life of me why I dropped it or just stopped reading.
I Think it's "Virtues of the Villainess". I need to read up a bit to make sure it is that one, but the cover art came to mind when I read your description. edit: hmm no, not this one, but I do know the one you are talking about, the "knight" girl was a cultivator or something.
No sorry that’s not it! I’m pretty sure the art style was not that bright !!! Yes that’s the one thank you!