Christie's notes for this follow, "Bridget Gunning (née Bourke), born circa 1715, was the daughter of Theobald Bourke, 6th Viscount Mayo. She married Colonel John Gunning of Castle Coote, County Roscommon, and they had two daughters, Maria (1732-1760) and Elizabeth (1734-1790). Indeed, Bridget Gunning's fame rests upon her determination to launch her daughters into London society, despite her husband's limited income. Around 1750, the Gunnings moved to London, where the beauty and charm of their daughters caused a furore in society. Bridget Gunning must have been delighted with the outcome of her efforts: both her daughters married in 1752. Maria married George William Coventry, 6th Earl of Coventry, and Elizabeth married Sir James Hamilton, 6th Duke of Hamilton. After her first husband's death, Elizabeth remarried in 1759, becoming the wife of Field Marshall Sir John Campbell, 5th Duke of Argyll. The sisters inspired two reels: 'Miss Gunning's Delight' and 'Miss Gunning's Fancy' and 'May the Luck of the Gunnings attend you' is still a proverbial Irish blessing."
Her brief article in thepeerage is here.
From stanford.edu/group/fam/cgi-bin/family/individual.php?pid=I18538&ged=auden-bicknell.ged&tab=0; image made lighter by gogm.