Finlay enrolled at Edinburgh College of Art in 1917, where she befriended her teacher Dorothy Johnstone and became part of the circle which included Cecile Walton, Eric Robertson and other artists involved with the Edinburgh Group. Finlay, or ‘Spook’ as she was affectionately known, was described as being very attractive and vivacious, often sitting as a model for her artist friends. She moved to London in 1922 where she painted predominantly portraits in oil. She exhibited regularly in London at the Royal Academy and with the Society of Women Artists, meanwhile maintaining her links with Scotland by also showing frequently at the Royal Scottish Academy. During the war, Finlay painted more landscapes, as she led a wandering life settling at times in different rural places in Sussex and Yorkshire. When the war ended, she returned to London to work as Registrar of the City & Guilds of London Art School, Kennington. Upon retirement, the artist eventually settled in Richmond, where she dedicated herself fully to painting until her death in 1963.