Captain Harrington Campbell Onslow1 
He gained the rank of Captain in the Royal Navy.1
Children of Captain Harrington Campbell Onslow and Helen Jane Allardice
- Mary Douglas H. Onslow2 d. 1871
- William George Onslow1 b. 1865, d. 1867
- Douglas Astley Onslow1 b. 1867, d. 1867
- Alexandrina Maria Onslow1 b. 27 Jan 1868
Helen Jane Allardice1,2 
From 8 December 1864, her married name became Onslow.1
Children of Helen Jane Allardice and Captain Harrington Campbell Onslow
- Mary Douglas H. Onslow2 d. 1871
- William George Onslow1 b. 1865, d. 1867
- Douglas Astley Onslow1 b. 1867, d. 1867
- Alexandrina Maria Onslow1 b. 27 Jan 1868
William Patrick Allardice1,2
Children of William Patrick Allardice and Anna Maria Macdiarmid
- Colonel John McDermid Allardice+2 b. 25 Feb 1835, d. 17 Dec 1905
- Helen Jane Allardice+1 b. 29 Oct 1837, d. 20 Jul 1871
- William Alexander Allardice+2 b. 19 Aug 1839, d. 12 Nov 1897
- George J. C. Allardice2 b. c 1842
- Maria Georgiana Elizabeth Allardice2 b. 24 Apr 1844
Elizabeth Steer Riding1 
From 5 April 1873, her married name became Onslow.1
- [S37] BP2003 volume 2, page 3015. See link for full details for this source. Hereinafter cited as. [S37]
Roger Riding1
Child of Roger Riding
- Elizabeth Steer Riding1 d. 31 Oct 1904
- [S37] BP2003 volume 2, page 3015. See link for full details for this source. Hereinafter cited as. [S37]
Alexandrina Maria Onslow1 
- [S37] BP2003 volume 2, page 3015. See link for full details for this source. Hereinafter cited as. [S37]
Douglas Astley Onslow1,2 
William George Onslow1,2 
Colonel George Manners Onslow1 
Children of Colonel George Manners Onslow and Louisa Cooke
- unknown Onslow1
- Ethel Georgy Udea Onslow1 b. 15 Apr 1873, d. 1963
- Ethel Mary Onslow1 b. 6 Feb 1877, d. 30 Dec 1965
- [S37] BP2003 volume 2, page 3015. See link for full details for this source. Hereinafter cited as. [S37]
Louisa Cooke1 
From 1871, her married name became Onslow.1
Children of Louisa Cooke and Colonel George Manners Onslow
- unknown Onslow1
- Ethel Georgy Udea Onslow1 b. 15 Apr 1873, d. 1963
- Ethel Mary Onslow1 b. 6 Feb 1877, d. 30 Dec 1965
- [S37] BP2003 volume 2, page 3015. See link for full details for this source. Hereinafter cited as. [S37]