Afterward, she studied acting at the Estonian Academy of Music and Theatre in Tallinn under course supervisor Elmo Nüganen, graduating in 2012 after appearing in diploma productions in works by Neil Simon, Molière, Alexander "Sasha" Pepelyaev, and Polly Stenham.

Lass has appeared in a number of stage productions by such authors and playwrights as: Shakespeare, Tom Stoppard, Peter Barnes, Diana Leesalu, William Boyd, Rodney Ackland, Jean-Luc Lagarce, and David Lindsay-Abaire, among others.

[10] It also bears some resemblance to the Dyatlov Pass incident of 2 February 1959, where nine ski hikers mysteriously died in the northern Ural Mountains after establishing a camp on the slopes of Kholat Syakhl.

[11] In 2018, she appeared as Moonika, a young mother who abandons her newborn infant to the care of her ex-boyfriend, in the Liina Triškina-Vanhatalo-directed Allfilm drama Võta või jäta.

[12] In 2022, she appeared in the role of Liis in the Ergo Kuld directed and period romance-drama Soo, screen written by Martin Algus and based on the 1914 novel of the same name by Oskar Luts.