Heroine? Saint? No, I'm an All-Works Maid (And Proud of It)! (Manga) Vol. 3 by Keiko

Melody is reincarnated into an otome game and ends up working as a maid for a poor count's family. She happily does her job to the best of her ability, not realising that her involvement improves every task she completes. Unbeknownst to her, Melody is actually a saint and the heroine of the game! Will she ever find out the truth and fulfill her destiny?
Binding: Paperback / softback