The singer opens up about adapting her memoir for TV and contributing a Christmas single to the 'Happiest Season' soundtrack. Clea DuVall's queer Christmas rom-com also stars Alison Brie and Dan Levy.

As well as Stewart and Davis, Happiest Season also boasts the acting talents of Schitt’s Creek star Dan Levy, Mary Steenburgen, Victor Garber, Alison Brie, Aubrey Plaza, and Mary Holland.

Alison Brie (Apples Never Fall ... In film, her recent credits include Somebody I Used to Know, Spin Me Round, Happiest ...