Hi Heather - I found another connection a better one.
Having another look I see that my great great great grandfather Michael Martin who married his cousin Jane Martin, well Jane and your catherine are sisters.
I will try not to confuse you here -
John Martin Married Catherine Martin (these are Catherine's parents, it seems the martin family like to marry their cousins)
Info I have on John Martin
B.C 1800 in St Agnes (? error for St. Gluvias)
Bap. 18 Jan 1801 at Stithians.
Miner of Ponsanooth 1820
Labourer of ST. gluvias 1821
Miner of St. Gluvias 1822
Powder-maker of St Gluvias 1824
Gunpowder manufacturer of St Gluvias 1825 and 1828
Miner of St gluvias 1837
Lavourer of Laity Moor in St gluvias, aged 40, 1841
Copper-miner of Tregost in Stithians, aged 51, 1851
Illiterate.
Info I have on his wife Catherine Martin
Daughter of Henry Martin,(who was a labourer of st Gluvias) and mother was Catherine Thomas
Bap 24 sep 1794 at Stithians
Married John Martin 8 Aug 1819 at Perranarworthal
Died 2 Aug 1854
Bur. at Stithians
Illiterate
Children of John Martin and Catherine Martin
James Martin Bap 23 Mar 1820 at Perranarworthal (Labourer)
Edward Martin - Bap 24 Mar 1822 at Perranarworthal
Elizabeth Martin - Bap 10 April 1825 at St Gluvias married Charles Williamson, cordwainer of penryn, mar 29 feb 1852
Catherine Martin - Bap 3 June 1827 at St . Gluvias Married Nicholas Dunstan
Jane Martin - Bap 5 oct 1828 at St Gluvias married Michael Martin miner of Stithains 11 Aug 1849 and Emigrated to australia in1851 (This is my line)
Ann Martin bap 26 mar 1837 at St Gluvias married thomas Knuckey, miner of Crellow in Stithians mar 29 dec 1849 in stithians
Mary Martin bap 26 mar 1837 at St Gluvias, emigrated to Australia at the age of 19 in 1856, she was a servant in Ballarat, she married Thomas Prish, miiner of Ballarat. They married on the 16th aug 1856 at ballarat (he died 1912 aged 79 at oakleigh in Victoria.
John Martin bap 2 april 1821 at St gluvias. (Powder maker) emigrated to australia on the ship the 'Pakenham' arrived at adelaide, SA 23 mar 1849. died 21 March 1896, aged 76 at Bridge Road Richmond Meilbourne, Victoria, he was literate.
married first Ann (nanny) weeks 25 dec 1845 at St gluvias, she died 5 dec 1873 at Scotchmans lead, Bunninyong Mine, Ballarat
then married Margaret Morton, widow of mount pleasant in Ballarat, she had 10 children by her 1st husband.
they married 3 amr 1891 by lic, at Ballarat.
They moved to Western australia and she died 11 oct 1931 at Leederville, bur, karrakakatta Cemetery
William Martin - bap 12 sep 1824 at St gluvias. - Emigrated to Australia 1848 - first to South australia for 4 years and then to Victoria. Died abte 1875 at Avoca in Victoria
He married Jane (or fanny) possibly died in Austrlaia, she had 3 children who died young. she died about 1852
2nd marriage to Margery Penhallurick on the 30 april, 1856 at Ballarat, Victoria.
She remar. 1 nov 1875 at Avoca in Victoria, John Nichols Simmons (a cornishman form camborne) by whom she had a son - John Charles Belman simmons B 5 nov 1877.
Heather I could go on and on, I can follow both lines of John martin and catherine martin back.
If you want this let me know ok.
I have a full history on my martin family and most brothers and sisters so let me know else you need and I will forward it on
Megan