Sarah Marshall Family - possibly Drumragh, County Tyrone

Sarah Marshall born 1848-1849 County Tyrone, married Stephen Walker on 1 October 1866 at Drumragh, County Tyrone. Her father given as George, his father given as George as well. She named her children: Stephen, George Marshall, Mary Lowe, and Sarah Jane. She died 16 January 1909 at Carrickfergus, County Antrim. Would like to find her family, but not having much success. Much appreciation for any assistance.