Hi Ray,
I am also descended from Isabella Kelly and Joseph Clarkson. Their son William Clarkson (b.1840) was my great great great grandfather.
I have a record of their marriage:
Marriage: 2 Jan 1832 St Mary the Virgin, Prestwich, Lancashire, England
Joseph Clarkson - (X) of Oldham
Isabella Kelly - of Oldham
Witness: Simpson Lloyd; Abrm. Kay
Married by Banns by: Thomas Tolming
Register: Marriages 1832 - 1834, Page 402
Source: LDS Film 2356186
from ht tp://www.lan-opc.org.uk/indexp.html
I was wondering if you've found any further information since this post. I have been unable to find anything conclusive regarding Isabella's family in IOM.
I have her born around 1811, based on her age in the 1841 census.
I would love to hear if you have been able to dig up any further information! I can be reached at terrafish@gmail.com
Jessica