I Reincarnated as a Faint Hearted Countess is a Manga/Manhwa/Manhua in english language, REINCARNATION series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

The cowardly Countess Ram, who is constantly lambasted by her maids, is having an ordeal at the place she was wed. She is supposed to be a newlywed, but her husband, the Count, didn’t even pay regard to her. Then one day, she hits her head on a wall and regains her memory of her previous life. Ram of the previous life was a great witch who was touted as the most powerful in the country. Fed up with her cramped life, she decides to live on her own terms, taking advantage of the memories she regained.