Heroine? Saint? No, I'm an All-Works Maid is a Manga/Manhwa/Manhua in (English/Raw) language, REINCARNATION series, english chapters have been translated and you can read them here. You are reading chapters on ManhwaZ fastest updating comic site. The Summary is
Melody reincarnates into the world of an otome game and works as a maid. As someone who has never played an otome game, what she hasn't realized is that she's actually the saint, the heroine of the game.