An early exponent of Canadian modernism, Coonan was brought up in Point St. Charles, Montreal. She took art classes first at Conseil des arts et manufactures, and later at the School of the Art Association of Montreal, where William Brymner became her teacher and mentor. Another important influence was the work of James Wilson Morrice, whose work she admired. Coonan became a member of the Beaver Hall Group, an important assembly of artists in Montreal which came together in 1920, named after their studio location at 305 Beaver Hall Hill.
Figurative work was a primary focus for Coonan in the early part of her career. She took a modernist approach in which the emphasis was less that of a traditional portrait that seeks to express the personality of the model, but more on the aesthetic concerns of the painting as a whole - form rather than content. Importantly, the exhibition of this work in the 1910 Annual Spring Exhibition at the Art Association of Montreal was a significant landmark for Coonan. Antaki writes, "With the inclusion of Evelina, 1830, and three other works in this, the 26th Spring show, her 'professional' career was well underway. What is most striking in Evelina is its utterly unselfconscious demeanor and the confident, yet delicate manner in which it was executed." The Herald newspaper reviewed the show, proclaiming that, "the oil Evelina, 1830 an arrangement in lavender, violet and white indicates the work of a born colorist of more than average talent." There is speculation that the model could possibly be Coonan's sister Eva, as she had painted her before in period costume in the 1907 work Eva and Daisy. There is also the possibility that the image derives from Fanny Burney's novel Evelina (or a Young Lady's Entrance into the World), as Coonan was an avid reader and loved the classics. In any case, although Coonan uses a more historical form of dress, the work is distinctly modern in its treatment, with the sensitive modulated background stripped of all detail, and the very painterly, brushy approach to the details of the dress. The stance in profile makes the work less a portrait and more a classic universal study in feminine beauty and grace, with an evocative, lyrical mood. It also gives emphasis to the wall and floor, whose sensitive colour surfaces contribute to the atmosphere of the work. In this refined and beautiful painting, Coonan fully explores the formal aesthetic qualities of art through the figure. It is interesting to note that Evelina sold for $50 - quite a considerable price in 1910 and a reflection of her importance. In 1987, this magnificent painting was included in Concordia University's important one-woman exhibition of Coonan's work, and was illustrated in the catalogue for the show.
Coonan traveled to Europe in 1912 with Beaver Hall Group member Mabel May, visiting France, Belgium and Holland. She was awarded a National Gallery of Canada traveling scholarship in 1914, but because of the war had to wait until 1920 to 1921 to enjoy a full year painting in Europe. Most of her exhibiting history took place in the first part of her life; between 1908 and 1924 Coonan contributed to many of the annual exhibitions at the Art Association of Montreal and the Royal Canadian Academy. After 1925 she exhibited less frequently, with 1933 being her last show. Although other women from the Beaver Hall Group continued their ties throughout their lives, Coonan did not. However, she continued to paint until the end of her life, and for the next 30 years she chose to work on her own, sketching en plein air during regular excursions in the Quebec countryside with her family. Her landscapes derived in style from the continuing landscape tradition in Quebec. Although Coonan's paintings, due to her more private life after 1933, were not often seen for a time, the recent attention to the fine work of the Beaver Hall artists has brought the spotlight to her accomplished career again.
This noteworthy painting was purchased by some lucky patron of the arts for, $46,800.00 at Heffel's recent auction in Vancouver.