Hello Liz, have you checked out the following,

Robert Cain and Eleanor Crebbin
Marriage, 11 October 1856 Arbory

You need to check if any Children between 1856 and 1861 Arbory and German

Children,
Eliza Jane Cain 29 March 1861 German (could this be the Elizabeth Oates on the 1881 Census below, with Brother, John Cain)
Emily Cain 2 May 1863 German
Emily Cain 27 November 1863 German
Robert Henry Cain 17 May 1865 German Died, 3 Nov. 1870

Check for more Children after 1865 in Parish Register German

Also check in Census for,
Robert and Eleanor Cain, 1861, 1871, 1881, 1891

Check for Eleanor in 1901 Census

1881 Census RG 11 / 5607
Malew
William Oates 27 Blacksmith Ballasalla
Elizabeth Oates 24 Ballasalla
John Cain Broth in Law Apprentice Blacksmith Ballasalla (Brother in Law to the Head of House, William Oates)

From online IGI

Margaret Elizabeth CAIN and William Hampton OATES
Married, 8 July 1879 Malew

From, www.manxlawsons.ca

Children,
Oates Catherine Ann 5 Oct. 1882 Malew
Oates Frank 1 April 1885 Malew
Oates William Robert 27 April 1887 Malew
Oates Henry 25 June 1888 Malew
Oates Eddie 13 Jan. 1891 Malew
Oates Lilian Margery 12 May 1896 Malew
Oates Mona Issabel 9 Oct. 1900 Malew

Hope this helps,

Averil