Hi,
The baptism I found had parents Thomas and Susanna, I found the baptism using Ancestry. I can also find the following,
St Botolph Bishopsgate, London
Baptism: 5 Dec 1759
James MASTERS
son of Thomas & Susanna
St Giles in the Fields, Holborn
Baptism: 07? Oct 1760
Eliz MASTERS
of Thomas & Susan MASTERS
St Giles in the Fields, Holborn
Baptism: 13 Jul 1762
Sarah
of Thomas & Susanna MASTERS
Saint Anne Soho,Westminster,London
George MASTERS
Birth Date: 04 Dec 1763
Baptism Date: 26 Dec 1763
Father: Thomas
Mother: Susana
St Dunstan in the West, City of London
Baptism: 22 Apr 1770
Charles Thomas
son of Thomas & Susanna MASTERS
born March 29 White Friars
I can't tell if these are the same Thomas and Susanna but they are all born in a small area of London.
I found this marriage using FindMyPast,
Southwark St Olave, Surrey
Marriage: 02 Dec 1759
Thomas MASTERS
Groom's place/parish: Middlesex - St Giles in the Fields
Susanna CONSTABLE
This would be a good fit for Sarah but a bit close for the 05 Dec 1759 baptism of James.
Daisy