Interesting thread, sorry I am a decade behind, but only recently began looking at my Irish ancestry again.
> Incidentally, my mother, Sheila, is most curious to know > if your Aunt Jeannie knows anything of her grandfather > William's wife, Margaret McGimpsey (nee Mahwhinney)
Margaret was born about 1863, married 21 February, 1881. Her father John Mawhinney was a publican on Frederick St, and later spirit dealer there and on Mill St. The trade directories show in 1852 Kenneth Mawhinney was a publican on Frederick Street, likely father of John.
My gt-grandfather James Mawhinney was born about 1869 to father John, publican. Not specified his father was the same as Margaret's, but the trade directories only show one publican John Mawhinney at Newtownards that period, so I assume Margaret and James were brother and sister, Richard that would set us as third cousins.
James Mawhinney married 1886 to Charlotte Smiley from Whitespots, Charlotte's parents Alexander Smiley and Catherine Goudey, 1911 census suggests that couple born 1838 and 1834.
Alexander Smiley looks to have been son of Hugh Smiley and Mary Wallace at Whitespots. Seem to recall somewhere in this thread a McGimpsey married a Wallace at Whitespots, I wonder if that couple were parents of Mary?