Simonin was born in Switzerland in 1936, and spent her childhood and summer vacations in Champex, in the canton of Valais. She received her degree from the École cantonale des beaux-arts de Lausanne in 1958, and was awarded a national arts grant in 1963. Simonin has lived and worked in Montreal since 1968, the year she first received a grant from the Canada Council for the Arts. She taught visual arts at the Université du Québec à Trois-Rivières from 1970 to 1994. Over the course of her prolific career, Simonin has presented more than two hundred solo exhibitions, primarily in Switzerland, Canada, France, the United States, and Spain. The Musée d’art contemporain de Montréal accorded her a solo exhibition in 1975. In 1989, she exhibited at the Musée cantonal des beaux-arts de Sion, in a Jesuit church, and, in 1992, the Musée Jenisch de Vevey held an important retrospective. Simonin has received numerous honours and awards, notably the first prize at the Biennale Suisse de gravure in Geneva (1968); the Prix Loto-Québec, in Montreal (1981); the Prix Irène-Reymond, for lifetime achievement, in Lausanne (1986); the Grand Prix de la Fondation Vaudoise, for artistic creation and promotion of the arts (1990); the prize for printmaking at the Biennale du dessin, de l’estampe et du papier, in Alma (1993); and the first prize at the sixteenth annual Mini Print Internacional de Cadaqués, in Spain (1996). In 2004, the Musée national des beaux-arts du Québec awarded her the Fondation Monique et Robert Parizeau Prize in recognition of her printmaking oeuvre, and, in 2011, the Fondation Pierre Gianadda, in Martigny, Switzerland, honoured her with a retrospective exhibition accompanied by a monograph.