[1] She moved to Los Angeles at 11 years old, where she began to study theatre at the Adderley School.
[7] Gallagher has done many live shows where she performs her music in Los Angeles and New York City.
She auditioned for the part after a suggestion from fellow theatre actor Ben Platt.
[9] Gallagher has done several television projects, her most notable role being Annika in the Lifetime series You, in which she appeared in eight episodes of Season One.
[11][12] In 2019, Gallagher joined the cast of Jagged Little Pill on Broadway in the role of Bella Fox.