Margaret Anne Warnock nee Maxwell is my gggrandmother,parents were William Maxwell and Eliza McDonnell,have specked that their father was Thomas Maxwell and Margaret of Corrog/Corrock as on lease for Ballygraffin mentions names of a Thomas and an Andrew Maxwell,though only guess work .On will of Samuel Mcgiffert has a Thomas Mcdonnell of Ballyspurge and William Maxwell of Ballygraffin mentioned.I believe Eliza McDonnell's family came from Ballyspurge as a Thomas Mcdonnell is witness to the marriage of William Maxwell of Ballygraffin.
The tithe leases of the 1820'ies have a William Mcgiffert of Ballytrustan entered,son was James Mcgiffert who married a Rose McKibbin,daughter of Thomas Mckibbin of Killydressy,mother was a Maxwell.
james Mcdonnell of Portaferry married a Rachel Mcgiffert,a daughter Susan died at her aunts house at Corrock Cottage,a Isabella McGiffert as per death notice.
I notice a Henry McGifford maried a Mary Mcdonnell in the igi index just before Henry and Robert and William were born.
Hope this helps abit as I am interested in understanding the family connection with the mcgifferts.