Bertin initially studied philosophy in Paris before beginning her training at the Studio-Théâtre of Asnières in 2009. In 2011 she was accepted to the Conservatoire Nationale Supérieure d 'Art Dramatique, working primarily under the direction of Dominique Valadié, Nada Strancar, Daniel Mesguich, Alain Zaepffel, Sylvie Deguy, Caroline Marcade, Yvo Mentens and Georges Lavaudant. In 2012, she staged an adaptation of Wedekind's Spring Awakening at the CNSAD. The following year she directed Berliner Mauer: vestiges, together with Jade Herbulot, with whom she would also found the Birgit Ensemble.
The Birgit Ensemble's second work, Pour un prélude, was produced at the Théâtre de la parenthèse in Avignon, then performed at the Théâtre de Vanves, and toured in 2016 and 2017.
In 2014, she collaborated with Robin Causse on the text and direction of Narcisse! Tu perds ton corps, and performed it solo on the Parisian stage »La Loge«.
In 2015 she performed under the direction of Kevin Garnichat in Le Dilemme du possoin-chat at the Studio-Théâtre of Asnières. Since 2016, she has appeared in L'Héritier de village by Sandrine Anglade at the Centre Georges Simenon in Rosny-sous-Bois and on tour. The Birgit Ensemble's two latest productions were shown at the 2017 Festival d'Avignon.