She has a sister, Willa, who is a singer, and two half-siblings: Clara, also an actress and director; and Noah.

She lived in New England until age five when her mother moved to Pacific Palisades, California, with Willa and Zosia.

She has subsequently appeared as a regular in television series such as The Flight Attendant, The Decameron, and Laid.

Mamet has also done voice-over work in Star vs. the Forces of Evil, Regular Show, and The Simpsons.

[14] At the 2017 Makers Conference, Mamet performed a monologue describing her experience of living with undiagnosed pelvic floor dysfunction for six years.