She became interested in acting at age 14, after playing a small role in a community theater production of Seven Brides for Seven Brothers.

[5] She had moved to New York City to pursue stage work when she landed an audition for ABC's Once Upon a Time, after which she was cast as Anna in the fourth season of the series, released in 2014.

[8][9] In 2017, Lail was cast as Guinevere Beck in the Lifetime/Netflix television series You, opposite Penn Badgley and Shay Mitchell.

[21] In January 2023, Lail was cast as Vanessa in the film adaptation of Five Nights at Freddy's, which premiered in October of that same year to commercial success.

[22][23] In April 2021, Lail married dentist Nieku Manshadi at Hasbrouck House in Stone Ridge, New York.