My mother's book is available on demand at Higginson Press, Salem MA -- no royalties paid, unfortunately. If you want my book, it is available.However, it is limited to the descendants of Abraham Josselyn and Beatrice Hampson. It includes many Canadian families who descend from Samuel Joslin who was born in New Brunswick, son of Moses Joslin, a Loyalist from a New Haven CT family who received land in NB and settled there in Oct. 1786. If you are married to Keith, you are from this family, and in my book.
Andrew Joslin, another Loyalist, from a Rhode Island family. also settled in New Brunswick a few months after Moses did. Like Moses' descendants, some live in Canada, and some live in the U.A.
Other Joslins and Jocelyns in Canada seem to be descended from later arrivals there.