Mary White, affectionately called Mama, serves as the matriarch of the White family. She is married to George White and mother to twin daughters Hello Kitty (Kitty White) and Mimmy White. Her appearance is that of a white bobtail cat, typically rendered without a visible mouth, though some portrayals depict her with one. She consistently wears a yellow bonnet featuring a red bow, an apron over a long dress, and shoes. Mama stands equal in height to her husband, roughly twice the size of her daughters.

She embodies kindness, care, and a sunny disposition. Worry or sadness surfaces when family well-being is concerned, often quietening her. Her primary household duties involve sewing and cooking, with baking being a noted skill she passed to Hello Kitty. She also runs a successful mending business, repairing clothes for neighbors and friends in exchange for payment. For formal occasions, she exchanges her usual dress for a dark brown cardigan and beige dress while keeping her signature bonnet and shoes.

Mama demonstrates reasonableness and offers steady emotional support, especially mediating conflicts between her daughters. For example, during a baking mishap where Mimmy became distressed over Robert consuming a poorly made pie, Mama resolved the situation through calm conversation. She holds a fondness for roses, which Hello Kitty sometimes gifts her.

Her background places her within a British family residing in a London suburb. Her birthday is September 14th, aligning with the Virgo zodiac sign. Expanded lore credits her as the source of Hello Kitty's iconic red bow in certain media interpretations.