meles,
Someone has posted this message on a Norfolk message board about James 1806 sisters, if I read it correctly
I would have to consider these sister's relationship to James as unverified.
"James Rivet b.1806 from Kenninghall, Norfolk, England left and came to Canada. He then went to New York State and married. His father was James Rivet and his mother was Abigail Knights. He had two sisters, Matilda b. 1808 and Sophia b. 1838. His line in the United States has been extensively researched. Looking for others related in England or any knowledge."