Ikai kara Seijo ga Kitanode Oyaku Gomen ni Narimashita: Shokei Saresou nanode Kakushita Chikara wo Kaihou Sasete Itadakimasu!

After discovering she has the powers of a saintess at the age of five, Estelle is forced to work day in and day out for much of her life. Fearing she'll be worked even harder if her true powers are revealed, she decides to hide just how powerful she really is. As long as she can eat every day and have a roof over her head, she even decides to put up with the snot-nosed crown prince of the country and gets engaged to him. Just when she believes her days of struggling to survive had ended, a girl from another world arrives and catches the prince's eye! He breaks off their engagement and brands her a "false saintess," ordering her execution. Fed up with all the idiocy, she unleashes her full power and puts the prince and his followers in their place. Finally free, where will she go with this newfound freedom...? (Source: MangaPlaza)