I really do not think that this book would be of much help to you because it basically relates to the Cosby Family that settled and lived in Virginia.
Alexander Cosby, Esq of Stradbally Abbey who married Dorceas Sidney had a son named Charles Cosby born 12 Sept 1585 who came to Virginia around 1628 and settked in either York or Warwick Co. He married Mary Loftus who died in 1623 before he came to Virginia. It was John Cosby the son of Charles Cosby and Mary Loftus who born in England in 1623 and apparently came to Virginia with his father.John Cosby is the Cosby to whom all of the Cosby Family in this book can trace their ancestry.
I have not seen any reference to any of this Cosby Family having settled in Canada.