Even if her great aunt could sponsor her, it would not be fast. We are talking about months. She is US, she could maybe look into Bunac visa to get a work permit for 6 months, see
http://www.bunac.org/usa/workCanada/eligibility.aspx but she would need to be a student to get that. Otherwise, if she has any kind of experience doing anything, try to get an LMO like PMM said. Depending on the province, some low skill jobs are also in demand.