Frederick David Brewster was the son of John Fell Brewster and Sophia Brewster (née Wilmore also Willmore).
His father John Fell was born in North Somercotes, Lincolnshire, in 1850 (A/M/J Louth Lincolnshire), the son of David Brewster, a bricklayer. He married first Anna Maria Richardson at Hull St Mark on 11 August 1872 by whom he had at least five children, two of whom died in infancy; Alice Ann b. 1873 (d. 1874), Ernest Edwin b. 16 July 1875, Walter b. 1877, Herbert b. 1880 and Ann Maria b. 1883 (d. 1883). In 1881 the family was living in Great Grimsby, Caistor. John's wife died in 1883 aged about 34.
His mother Sophia was born in Caistor, Lincolnshire, in 1860 (J/F/M Caistor), the daughter of George and Susan Wilmore (née Clark m. 1848 Grasby Lincolnshire). In 1881 she was living with her parents on Brigg Road, Caistor. Sophia had a son George Thomas Wilmore in 1882. George was probably brought up in Caistor by his grandmother, Susan, until the age of eight after which he was in the care of a Mrs Jennie Wilson of Newark. He joined the Army in 1900.
John and Sophia were married in 1885 (A/M/J Caistor), two years after the death of his first wife, and had six children one of whom died in infancy. Their surviving children were: Alice Sophia b. Great Grimsby Caistor 1886 (J/A/S Caistor), Annie Maria b. Great Grimsby 1888 (A/M/J), John Willie b. Great Grimsby 1889 (O/N/D), Frederick David b. Nottingham 1898 (J/A/S) and Henry David b. Nottingham 14 February 1900.
In 1891 John, a bricklayer, and Sophia were living in Great Grimsby with three of John's children by his first wife - Ernest (15) a saw mill labourer, Walter (14) a bricklayer and Herbert (13) - and their two daughters, Alice (5) and Ann (3).
They had moved to Nottingham by 1901 where they were living at 7 Carsington Place with three of their five children John (11), Frederick (2) and Henry (1).
In 1911 John and Sophia were living at 40 Constance Street, Nottingham, with four of their children, Alice Sophia (24) a hosiery worker, John William (21) a twist lace hand, Frederick (12) and Henry (11).
Frederick and Sophia were living at 60 Gladstone Street, Hyson Green, Nottingham, when Frederick jnr. attested in 1914 and still living at the same address in May 1919 when Sophia completed a form for the army listing the surviving blood relatives of her son George Wilmore.
Sophia Brewster died in October 1927, burial 26 October, and her husband John died in September 1929, burial 7 September.
Frederick David married Florence Shipman (b. 5 February 1896) in 1917 (J/F/M Nottingham); they lived at 4 Hyson Passage, Nottingham. There were no children of the marriage.
His widow married Arthur Hooten (b. 14 January 1896) in 1920 (A/M/J Nottingham) and lived at 4 Hyson Passage, Lindsey Street, Hyson Green, Nottingham. In 1939 when the England & Wales Register was compiled Arthur, a circular sawyer wood, and Florence, a cleaner, were living on Wimbourne Road, Nottingham, with their daughter Joan (b. 27 May 1927) a telephone switchboard assembler. Florence died in 1988 (J/A/S Rushcliffe).