Next appears in Devil in Disguise: John Wayne Gacy, a limited series to air on Peacock. She also  continues starring opposite Paul Mescal and Beanie Feldstein in the Richard Linklater- helmed film MERRILY WE ROLL ALONG, which shoots over a 20 year period. She starred in HBO Max's Pretty Little Liars: Original Sin. At 16, she was hired to cover the role of Zoe in the hot Broadway musical, Dear Evan Hanson. The team liked her so much that they offered her the first Broadway replacement, and she deferred college in order to perform. Mallory appeared in the A24 hit feature film HEREDITARY opposite Toni Collette and Gabriel Byrne. She was set to play Kim in the Kennedy Center production of Bye Bye Birdie opposite James Van Der Beek and Harvey Fierstein before Covid 19 caused the season's cancelation. She was discovered on YouTube as an eleven-year old performing Defying Gravity.