I agree, JJ - that is exactly my reasoning for Newton's daughter to remain there, rather than returning to England after her father's death.
I've come across a bit more information...
Once Blind: The Life of John Newton - There is mention here of Captain John Newton going to York Factory for three years while his wife and three children remain in England. Page 140 at
http://books.google.ca/books?id=rqgg9hG9JooC&pg=PA140&lpg=PA140&dq=John+Newton+%2B%22Fort+York%22&source=bl&ots=LlgJIhp8px&sig=dD-_LOjkYcwW9_TLevDVHngUIgY&hl=en&sa=X&ei=dWiaUe-6NKScjALhgIGoCQ&ved=0CF8Q6AEwBw#v=onepage&q=Thomasina&f=false –
There's another mention of Captain Newton's second family years later - no preview for this entry but it does say that Harry was in Boston in the Royal Navy, Thomasina was happily married on Page 193.
A bit more info available at
http://www.westminster.coresense.com/pdf_files/newton_disgrace2amazing.pdf I did a search for Thomasina to locate the following...
John Newton’s father was away at sea when his wife died. He did not return from his Mediterranean travels until early in 1733. When he came home to discover that he was a widower, Captain Newton spent little time in mourning. He remarried quickly, taking as his second wife the daughter of “a substantial grazier” from Aveley in Essex. Her name was Thomasina, and her background was a relatively wealthy one, for in those days the difference between a farmer and a grazier was at least five hundred acres. Thomasina, who was of Italian descent, bore two sons and a daughter to Captain Newton. The arrival of these children resulted in John’s being sidelined into the predictable but unhappy position of a stepson who is excluded from the inner circle of the new family
Thomasina Newton (d. 1776)
Thomasina, an Italian, was Newton’s stepmother. It is thought the family lived at Moor Hall Farm on the property of Lord Dacre’s Belhus estate in Aveley. Her children by Captain John Newton were William, Henry, and Thomasina. According to Newton she lived “without the least thought of religion, never going so much as to a place of worship, except for the birth of a child.” (Cecil, p. 316)
Simon Scatliff (b. 1668)
Simon, a mathematical instrument maker of Paul’s Wharf London, was Newton’s grandfather. He had four children—John, Simon, Samuel, and Newton’s mother Elizabeth. In the marriage register Elizabeth’s maiden name was written as Seatliffe.
The Scatliff family came from a long line of mathematical and scientific instrument makers. For their genealogy see
www.scatliff.net.
Good Luck!!