I too am looking for information regarding a female Matheson associated with Red River Settlement: Janet Matheson whose birth date is 'guestimated' to be 1787 and recorded year of passing is 1866. She traveled with her new husband Angus Gunn (1788 - 1879) and members of his family on the 'Prince of Wales' as Selkirk settlers, leaving Stornway 1813 and arriving at RRS in 1814. I believe Selkirk Settlers with the Matheson name arrived in 1815 via Church Hill / Hudson Bay. Her and Angus's first child, Catherine was born 1814 RRS and she married a McIntyre...
When you identify the ancestors for your Catherine, it likely will relatives of my my gr.gr.gr. grandmother.
Actually, I believe I have identified Catherine's mother since that posting. The mystery lady is Catherine J. Morrison, born 24 Oct 1862 to John Pritchard Matheson and Anne Fraser. She married Angus Morrison and died two years later after giving birth to Catherine Matheson Morrison.
It has taken me about 30 years to track her down so don't despair about tracking Janet! Good luck!!