There were families known as Vachon, Vachon-Pomerleau and Vachon dit Pomerleau. In one generation, siblings could, would and did take different surnames.
Joseph David Vachon and Marie Celanire Georgiana Vachon dit Pomerleau were a pioneering couple with a large family. One daughter, Victoria Desneiges Vachon married Nazaire Poulin. Another of their daughters, Lucia Vachon married Raoul Poulin.