Manhua i forgot

Isekai, medical genre. Has a bitch of a sister with white hair. She is always wearing red the mc that is. Is in love with the prince, the prince is good is also in love with her. Uhhhh there is also the episode where she draws in the modern way all the people the empress, the prince, her mother and sister.....yeah I can't remember more. I know this is a pretty generic plot and I gave not much clues but pls help me find the manhwa