My Great Grandmother was Martha Pollock, she was born around 1847 - her father was also a George Pollock.
I checked on Emerald Ancestors, and it says there was a Sarah born on 23 May 1851 and baptized on July 3, 1851 at Donagheady Church of Ireland.
I found a listing of a George Pollock marrying a Sarah Pollock - whose dates match.
http://www.cotyroneireland.com/churchrecord/glendermott2.html - third item down.
(The only Martha Pollock I can find has a father George and mother Sarah - again baptized at the Dongaghheady Church, and her full name is Martha Bell Pollock - so I'm thinking Bell might be the name of one of her relatives?)
I wonder if they were sisters? I also found two brothers - James (1875) and Robert (1879).
Martha married an Andrew Nutt! And their son married Sarah Scott - who became Sarah McNutt (because my grandfather changed his name to McNutt!)
I love this stuff...!