Mary Joynes

Born: Abt 1729, Kensington, Middlesex, England
Died: 29 July 1770, London, Middlesex, England

Father: Henry Joynes, 1684-1754
Mother: Mary Peisley, ?-1746.

Spouse: Samuel Christian Frederic Baumgarten, 1724-1798
Married on 6 June 1751 at St George's Chapel, Mayfair, Middlesex, England.

Children:

Biographical information
There isn't an enormous amount known about Mary Joynes. She was the youngest of six (known) children of Henry and Mary Joynes, and was baptised in Kensington on 31 March 1729. 

She married Samuel Christian Frederic Baumgarten on 6 June 1751 at St George's Chapel, Mayfair. One wonders how they came to meet! At the time of her marriage, Mary's father was the Clerk of Works at Kensington Palace, so one imagines that the family might have moved in the same upper-middle class circles that Samuel Baumgarten might have had entry to, through his music.

We know Mary's date of death from the law suit her husband brought against members of her family, over inheritance money. These documents are found in the National Archives UK. She was buried at St Marys Hendon, on 4 July 1770, though the burial register records her surname as "Bumgarten".