In Feb 1733 [her father] Stephen Poyntz (age 47) and [her mother] Anna Maria Mordaunt were married.

On 20 Dec 1755 John Spencer 1st Earl Spencer (age 21) and Margaret Georgiana Poyntz Countess Spencer (age 18) were married at Althorp House, Northamptonshire [Map]. He the son of John Spencer and Georgiana Caroline Carteret (age 39).

On 07 Jun 1774 [her son-in-law] William Cavendish 5th Duke Devonshire (age 26) and [her daughter] Georgiana Spencer Duchess Devonshire (age 17) were married in St Mary's Church, Wimbledon. It was her 17th birthday. She by marriage Duchess Devonshire. She the daughter of John Spencer 1st Earl Spencer (age 39) and Margaret Georgiana Poyntz Countess Spencer (age 37). He the son of William Cavendish 4th Duke Devonshire and Charlotte Elizabeth Boyle Marchioness Hartington. They were fourth cousins.

On 27 Nov 1780 [her son-in-law] Frederick Ponsonby 3rd Earl Bessborough (age 22) and [her daughter] Henrietta Frances Spencer Countess Bessborough (age 19) were married. She by marriage Countess Bessborough. She the daughter of John Spencer 1st Earl Spencer (age 45) and Margaret Georgiana Poyntz Countess Spencer (age 43). He the son of William Ponsonby 2nd Earl Bessborough (age 76) and Caroline Cavendish Countess Bessborough.

On 06 Mar 1781 [her son] George John Spencer 2nd Earl Spencer (age 22) and [her daughter-in-law] Lavinia Bingham Countess Spencer (age 19) were married. She the daughter of Charles Bingham 1st Earl Lucan (age 45) and Margaret Smith Countess Lucan (age 41). He the son of John Spencer 1st Earl Spencer (age 46) and Margaret Georgiana Poyntz Countess Spencer (age 43).