Some details of this family:
Per his entry in "Contemporary Authors", 2004 ed. (replicated here-
https://www.encyclopedia.com/arts/educational-magazines/hunter-archie-1929) A. A. de C. Hunter was of Church House, Winsham, Chard, Somerset (not necessarily his last address, of course, given the date of publication), and was educ. Clare Coll., Cantab. (B.A. 1952, M.A. 1956), a barrister of Lincoln's Inn, assistant secretary, Ministry of Defence 1963-86, legal officer, International Commission of Jurists 1961-3, administrative officer, Government of Northern Nigeria, Colonial Service 1956-61, 2nd Lt, Royal Artillery, author of biographies of military officers (inc. Kitchener's Sword Arm: The Life and Campaigns of Sir Archibald Hunter; The Life of Sir John Eldon Gorst: Disraeli's Awkward Disciple). As Netty already provided, he m. 1955, (Rachel) Mirabel Steel, dau. of Sir (Robert) Donald Scott (1901-1974), of Caistron, Thropton, Northumberland, M.P. (s. of William Scott, of Newcastle-upon-Tyne, timber importer).
The 1929 birth record of Archibald A. D. Hunter gives mother's surname as "Atkins"; this is corroborated by the "Contemporary Authors" entry and some research, which shows him to be s. of Archibald Valentine Hunter (1901-1981), of Upper Combe Lodge, Castle Combe, nr Chippenham, Wilts., formerly of Marylebone, farmer, 2nd Lt, R.A.S.C. (WWII), and (m. 1928) Barbara de Courcy (1898-1982), dau. of John de Courcy Atkins (1860-1935), of Foxway Rise, Avenue Road, Fleet, Hants., formerly of Kensington and of Streatham, of the Indian Civil Service (inc. under-secretary to the Government of Bombay in 1886).
Per his entry in "Contemporary Authors" A. A. de C. Hunter's great-uncle (about whom he wrote the biography mentioned above) was Gen. Sir Archibald Hunter (1856-1936), G.C.B., G.C.V.O., D.S.O., T.D., senior general of the British Army 1914, late 4th (King's Own Royal) Regiment, M.P., Governor of Gibraltar 1910-13, Governor of Omdurman, Sudan 1899, Governor of Dongola Province, Sudan and Commandant of Frontier Field Force 1895. He m. 1910, Mary, dau. of Hickson Fergusson, of The Knowe, Ayrshire, and widow of George Burns, 2nd Baron Inverclyde. His Wikipedia entry has much more detail of his career etc.
With this information to hand, it was possible to establish A. V. Hunter's parents to be Brig.-Gen. George Gillett Hunter (1864-1930), of Halls Farm, Hartley Wintney, Basingstoke, Hants., educ. Loretto Sch., Sandhurst, Military Administrator, Frontier Districts 1917-21, of the Coastguard Administration, Egypt in 1896, having joined the Egyptian Army in 1888, of the Buffs (Royal East Kent Regiment) from 1885, C.B. 1916, C.M.G. 1912, and Hylda Marion (1867-1944), dau. of Rt-Hon Sir John Eldon Gorst, P.C., K.C., F.R.S., Vice-President of the Committee on Education 1895-1902, Solicitor-General for England and Wales 1885-6 (about whom A. A. de C. Hunter wrote the biography mentioned above).
References to Gen. Sir Archibald Hunter indicate his parents (therefore those of George Gillett Hunter) to be "London businessman" or "merchant" Archibald Hunter (1805-1868) and Mary Jane (née Graham[e]); the senior Archibald's probate record gives him as "warehouseman", of 10, Cannon Street, London, and of 26, Carlton Villas, Maida Vale. A (paltry and near-useless) snippet view of the biography of Gen. Sir Archibald Hunter states that the senior Archibald's father was yet another man of that name, b. 1768, per the author's description, a "tailor burgess" of Glasgow.
Netty has mentioned the marriages of A. A. de C. Hunter's daughter (Daphne) Clare; his son, Archibald James de Courcy Hunter (1957-), of Moor Farm, Ludlow, Salop., director of a cake company, m. 1st (div. 2001) Antonia Wendy Aileen (1958-), dau. of (Philip) Anthony Maunsell Gell (1921-1998), of Morfe Hall, Morfe Hall Lane, Enville, Stourbridge, West Midlands. He was managing director of the family firm, British Heat Resisting Glass Co., and founder of Elemelt (Kingswinford, Dudley, West Midlands), having been Col, Coldstream Guards. He was s. of Lt-Col Philip Victor Willingham Gell [1897-1970], of Hopton Hall, Wirksworth, Derbys., of the Royal Artillery, High Sheriff of Derbyshire 1953 [see GELL of Hopton Hall, GELL, Bt, MIDLETON, E. etc], and Aileen Edith Pauline [1895-], dau. of Col George William Maunsell (1859-1937), of 20, Gloucester Terrace, Paddington, Middx., of the Queen's Own Royal West Kent Regiment, C.M.G., J.P., author, "The Fisherman's Vade Mecum" [see MAUNSELL, BIFR] and Virginia Wendy Hadden Todd. She was dau. of Maj. Hadden Royden Todd (1910-1944), of the Royal Artillery, solicitor, s. of Hadden Todd, of Willaston Grange, Willaston, Cheshire, solicitor (this family does not appear to be in Burke's, but is in Armorial Families and other sources indicative of status not far removed from the families of interest here), and Evelyn Mary, dau. of Sir Thomas Bland Royden, 1st Bt.
Antonia Wendy Aileen Hunter née Gell m. 2nd, (William) Roderick ("Rory") MacDonald (1949-2015), of Burcot Manor, Wrockwardine, Wellington, Telford, Salop., chief executive, British Racing Sch., trustee, Shropshire Youth Support Trust, O.B.E. 2007, personal executive to chairman of Carroll Group, London 1988-91, Maj., Royal Hussars 1972-88.