Shinjuu Kishi-sama no Senzoku Maid: Munou to Yobareta Reijou wa, Hontou wa Kishou na Seizokusei no Tsukaite Datta You desu

Tilia is a "talentless" girl born into a family of counts who have wielded magical powers for generations. She is despised by her family and treated like a servant, but for some reason, a cute divine beast becomes attached to her. Duke Alvis sees this and thinks she may have some kind of talent. Little by little, the two grow closer... This is the story of how an oppressed girl discovers her true abilities and is saved.

(Source: Kodansha, translated)