Gilberte Bussiere, 74, and two Italian priests were kidnapped on April 5.
"I spoke to Sister Gilberte this morning and her voice was strong and she was happy," said Josephine Badali, leader of the Congregation de Notre-Dame.
"She told me she had seen the doctor and from what we know at the moment, her health is good."
Bussiere, originally from Asbestos, Que., was kidnapped along with Gianantonio Allegri and Giampaolo Marta.
All three had been working as missionaries in Cameroon.
"She asked me to thank everyone who supported her and helped secure her freedom," Badali told a news conference in Montreal.
It is still unclear when Bussiere will return to Canada.
Badali said Bussiere was to meet with the Cameroonian president on Monday.