Toumanians’ tenth child and Avetik Isahakian’s godchild Tamar got her secondary education at the Gayanian School. Then she entered the technical department of Yerevan State University and soon transferred to the Construction Institute to study architecture. She worked at the studio of Alexander Tamanian and participated in design works of Opera and Ballet Theatre building and the government building. Later she worked at architect Mark Grigorian’s studio. She was the secretary of the Union of Architects, Chairperson of the Architectural Fund. During WWII she lost her beloved one and did not think about marriage any more. In 1966-1989 Tamar was the director of Toumanian Museum after her elder sister Ashkhen. During these years the second building of the museum was built, the "Lori Canyon" panorama was created, and Toumanian’s 100th anniversary was celebrated. It was Tamar’s idea to reconstruct Vernatoon (the Loft) in one of the Museum's corner, which she realized in 1985.