Following college, Mariam Petrosyan became a cartoonist at the Studio of Armenfilm in 1989. She subsequently moved to Moscow and worked at Soyuzmultfilm Studio. In 1995, she returned to Armenfilm, where she worked until 2007. She is married to Artashes Stamboltsan. They have two children. She is a great-granddaughter of the Armenian painter Martiros Saryan.