Born in Sainte-Félicité, Quebec, where her parents owned a restaurant, Boulay moved to the nearby city of Matane at the start of her adolescence, and studied literature at Cégep Limoilou.

In 1993, she represented Radio Canada at the "Truffe de Périgueux" festival held in Périgord, France, and was awarded the prize for Best Singer in the "Chanson francophone" category.

[7] Boulay made a number of media appearances in France in 1999, and, in the summer, sang again in the FrancoFolies de Montréal, where the live album Scènes d'amour was recorded.

Beginning 2001-2004, the French media began referring to Boulay as one of the grandes voix québécoises (great Quebecois voices) at the centre of contemporary trends in popular music.

Other singers grouped in this category included Lara Fabian, Céline Dion, Natasha St-Pier, Garou, Daniel Lavoie, Lynda Lemay, Bruno Pelletier and Roch Voisine.

In March 2019, she was one of 11 singers from Quebec, alongside Ginette Reno, Diane Dufresne, Céline Dion, Luce Dufault, Louise Forestier, Laurence Jalbert, Catherine Major, Ariane Moffatt, Marie Denise Pelletier and Marie-Élaine Thibert, who participated in a supergroup recording of Renée Claude's 1971 single "Tu trouveras la paix" after Claude's diagnosis with Alzheimer's disease was announced.