I assumed that Stephen Hare's wife could not possibly be the sister of Arra Ferguson, because surely Rachel Ferguson did not marry her own nephew.
I was wrong.
from William Canniff's "History of the Province of Ontario":
a quote from Roger Bates of Newcastle: "I have heard my mother say that uncle Ferguson, a magistrate who performed marriages..."
Roger Bates' mother was Amelia Hare, wife of Stoddard Bates of Clarke, Durham; Hamilton; and elsewhere.
Arra Ferguson served some time as Town Clerk for Haldimand, Northumberland and later at Hallowell, Prince Edward, where his brother Roswell ( 'Rozel' as the name Roswell was formerly pronounced and thus spelled) also served terms as Town Clerk.
So it is that Amelia Hare Bates' mother was a sister of Arra Ferguson, but her brother Richard Hare's mother was not!
Rachel Ferguson, sister of Arra Ferguson, married her sister's step-son, Richard Hare.
Frederica Ferguson, daughter of Arra Ferguson, married her first cousin John Hare, Richard's half-brother.
Richard Hare was born in 1777, the same year his father Stephen Hare's militia regiment from Kinderhook District was activated in the War. Rachel, Mrs. Richard Ferguson, Arra et al's mother, went directly to Canada with her younger children as soon as she was released from jail in Albany in 1779. So the first Mrs. Stephen Hare must have died and Stephen remarried within that two year interval. Stephen, according to Harold R. Hare's "Early History and Genealogy of the Hare Family", visited the Fergusons in the Bay of Quinte for two years from 1785-1787, before returning to New York to fetch his wife and children to come to Canada. Amelia Hare then was born in her father's absence, in the US in 1786. The two youngest children of Stephen Hare and Miss Ferguson were born in Canada.