With money from a legacy left by her grandfather she attended the boarding school of Betty Morehead for seven years.
The Graham family was known for their piety and Isabella became a communicant of the Church of Scotland at the age of seventeen at the Laigh Kirk, Paisley where Dr. John Witherspoon, who was later a signatory to the United States Declaration of Independence, was the minister.
[3] While visiting Scotland from America in 1785, Dr. John Witherspoon spoke with Isabella regarding returning to the United States.
[3] While living in America, Graham was a member of the New York Society Library along with many of the nation's founding fathers and other influential individuals of the time.
Although her borrowing history at the library spans only four months, Graham checked out thirteen books during that period.
The records of her borrowing history demonstrate her interests in historical and biographical works, as well as novels and travel diaries.
She also aided in organizing the first missionary society and the first monthly missionary prayer meeting in the city; was the first president of the Magdalen Society of New-York (founded 1812[6]); systematically visited the inmates of the hospital, and the sick female convicts in the state prison; and distributed Bibles to hundreds of families, as well as tracts prepared under her own direction.