I found these links in my searches, which may be helpful for you.http://familytreemaker.genealogy.com/users/w/i/l/Sharen-Will...http://wc.rootsweb.ancestry.com/cgi-bin/igm.cgi?op=GET&d...
Links found while searching for the kin of Isabella Irvine who married a John Walker (almost certainly in Ulster Province)& whose son James, born about 1820, lived in Aughnacloy, Co Tyrone (migrating with a wife and child to NSW Australia during The Great Famine).
These Walkers grew flax and were linen weavers in Clogher Valley. The Irvine family in above link had linen mills in Larne. I have also come across some Isabel/Isabella names in their line. I have no substantiated link but am working on possibility that the linen industry may be a link, although stations in life may not support this.
Finding early BDM is almost impossible in Ireland. Next stop Tithe Applotment & Rent Roll Books; maybe Estate papers.
So I may or may not be very distantly related. Either way, I hope the links prove useful.