Census records show that she had younger sister (by 5 years) born in Upper Canada, who lived in Ottawa. She lived in Fitzroy while married to William.
In the 1861 census, she is living with her husband William, step-kids, and her first daughter with William, Margaret A. (age 2 at the time, so pretty close to when the tintype of Sarah and Margaret was taken). She is shown as being born in the USA.
In the 1871 census, she is shown as being born in Ontario, living with William, and all the kids (except William V., who was living with uncle Charles Curtis) except Thomazine (who was married by this time), and Parker, who was not born yet, in Huntley township.