Thanks for the info! I have all these, and was hoping to find more.
My proof that James was a sister of Eliza is from the 1880 census of Newark, NJ. Jane Geddes Harper (daughter of James) was listed as a niece of Thomas Castles and his wife, Eliza Harper. One of James' children, James Ffolliot Harper, was born in Newark in 1852.
I was also puzzled about the distance between Sligo and Co. Armagh. The marriage record shows that Jane Geddes' father was Archibald. There was an Archibald living in Co. Down, which is also a bit of a distance from Calry. However, I am 100% certain this is the right couple. I suspect that James and Jane married there right before they emigrated to Canada.
James and Jane's children were:
1) Eliza Jane, born 19 April 1849 in Saint-Patrice-De-Sherrington, Les Jardins-De-Napierville, Québec, Canada, died 29 April 1919 in Highland, MI
2) William Henry, born 19 Oct 1850 in Saint-Patrice-De-Sherrington, Les Jardins-De-Napierville, Québec, Canada, died 21 May 1906 in Harwich, Ontario, Canada
3) James Ffolliot, born Aug 1852 in Newark, NJ, died 14 Jan 1911 in Kansas City, MO. His death record lists his mother as "GEDDES".
4) George, born about 1854 in Chatham, Ontario, Canada, died aft 1871
5) Frederick A., born 16 Nov 1856 in Chatham, Ontario, Canada, died 1 Feb 1939 in Detroit, MI
6) Jane Geddes, born May 1860 in Chatham, Ontario, Canada, died after 1915 in Newark, NJ
After Jane Geddes died, James remarried to Mary Ann Knapp and had a son named Benjamin Knapp born 17 Jan 1864 in Chatham, Ontario, Canada and died 19 March 1934 in Chatham, Ontario, Canada.