Baker was born in Summertown, Glengarry County, Ontario,[1] and raised from a young age by her aunt.[2] She became a teacher shortly after finishing school in Fort Covington, New York.
Her teaching career was as varied as it was wide-ranging. She first worked in Dundee, then held classes in New Jersey for a women's school. She moved to New Orleans not long afterwards to co-own another women's school just before the American Civil War. In 1878, she returned to Glengarry County to teach a private school.
In 1879, minister Donald Ross asked Baker to teach at a missionary school in Prince Albert, on behalf of the Presbyterian church. She accepted the offer, and trekked cross-country to arrive at the western territory in 1879. She earned a permanent teaching grant at the mission school in 1880.
In 1890, Baker relocated to the Makoce Washte reserves in present-day South Dakota, where she served as chief instructor at a school for Sioux refugees. She learned to speak Sioux, and regularly spoke Mass in the refugees' native language.[3] She remained teaching at Makoce Washte until her retirement in 1905.
