I have Isaac and Elizabeth on my family tree, but only one son is listed (probably lack of information on the geneologist's part...bless her heart for making this family tree!). He's not in your list: Seth Howard Yerex (b. 9/14/1824, Whitby, Ontario, Canada). He married Mary Ann Smallwood. They had several children, including Estella Mary Yerex, (b. 2/20/1867 Little Britain Canada). Estella and her husband, Arthur Cuthbert, moved from New York/Canada to Pasadena, California c. 1900 to get involved in the real estate out here.
I would love to know more about the Canadian branch of the family and am happy to share more of what I have.
--Michelle Deets California email@example.com