So this manhwa is about a girl she reincarnated and she became and princess but she kept vomiting blood but she's actually fine and it's normal , MC has purple eyes and white hair
https://www.mangago.me/read-manga/when_the_villainess_loves/
I think you're looking for this one. Not entirely sure though since I lost interest in it once the ML came into the story and all the other characters were sidelined.
I want a petition so we can kill that bitch who was supposed to be mc friend but that seems fake , must just be a bitch using her . Dumbass bitch , can't you recognise your own friend daughter oh you must be blind to not know . And that bitch Xian Er no one give shit bout you ok. Tell the fucking truth .