Don’T Mess With Mistress summary:

An ancient medical successor, reborn into a body of a poor little girl. Saying that she’s stupid? Laughing that she’s miserable? She’ll settle her problem with her evil sister in a second! In her reincarnated life, Lin Su er only wanted to beat up the scum man and slag woman, then live an easy life.but she won’t expect to have offended a most respectable man, wanting to escape after having her way to him, “Little girl, you’ll need to take responsibility, and I will teach you how”