From 2000 to 2002, Dompnier took professional training as an actor in the Ateliers du Sapajou in Paris, Marie furthered her education in 2003, at the Centre Dramatique National in Poitiers.

In 2012, she appeared for the first time in the cinema in Dante Desarthe's Je fais feu de tout bois, before securing a small role in the television series Caïn in 2012 and Détectives in 2013.

[4] In 2014, she played the role of Charlotte Poussin in the film Les Gazelles alongside myriad actresses including Camille Chamoux, also co-writer.

[4] Dompnier was spotted during a "face camera" staging, by director Hervé Hadmar, and offered her the main role of his TV series Witnesses on France 2 alongside Thierry Lhermitte in 2015.

[3] Thanks to this role of Lieutenant Sandra Winckler, she obtained the Golden FIPA of female interpretation at the Festival International des programmes audiovisuals of Biarritz 2015.