Mary Mctavish and Madeleine (Magdeleine) Letard St. Onge (Saintonge) is the same person. She was born in 1801 or 1802. Madeleine married Charles Lacombe about 1820 on Drummond Island, MI. Their daughter, Madeleine, was born about 1823 on Drummond Island, MI. Charles Lacombe, who was a voyageur, died about 1825. Madeleine Mctavish dit Letard St. Onge married Antoine Lafreniere on Drummond Island, MI in 1826.They moved to Penetanguishene, Ontario in 1828. Her daughter Madeleine Lacombe married Louis Langlade at Penetanguishene, Ontario.
The marriage record of Antoine and Madeleine states that Madeleine is the widow of Charles Lacombe.A copy of the marriage record is at Penetanguishene Genealogical Archives.