As Mary Steenburgen mentions, she was thrilled to join the impressive company of actors that Clea Duvall assembled for Happiest Season. Tons of familiar faces are feature in the new Christmas movie, including Mackenzie Davis, Victor Garber, Aubrey Plaza, Ana Gasteyer, and Dan Levy. But it was her special relationship with Kristen Stewart that singlehandedly ruined takes while filming Happiest Season.
