1851 census for Arbory shows :-

Thomas Qualtrough shoemaker in Colby age 43 born Arbory
Jane age 48 Patrick
Elizabeth age 17 Arbory
Thomas age 14 Arbory
William age 11 Arbory
Ann age 8 Arbory
Catherine age 4 Arbory

IGI includes Margaret christened 1830 but working at Balladoole as house servant in 1851. Also Richard christened 1838 but died age 4.

1881 shows:-

Jane Qualtrough widow (Thomas died C 1853) 78, Patrick
Elizabeth Kelly daughter 47 mariners wife Arbory
Elizabeth A. Spence 16 grand- daughter farm worker born in Peel

All living at Claghbane Road Arbory.

From here it gets complicated and speculative:-

Elizabeth Qualtrough married Stephen Thomas Kelly in 1877 he was the son of Thomas Kelly and Catherine Fargher, born 1855 died 1903. He was 20 years younger than Elizabeth ( not uncommon )and was listed as a sailor.
It looks like Elizabeth had a child to a Spence in Peel. There are one or two possiblities, particularly the William Spence's who married after 1865.
Please note she is listed as Elizabeth A Spence not Elizabeth J Spence.

The only John Christian born in Castletown to match Elizabeth in age was born to John Christian and Ellen Gell.

Hope some of this fits,

Len Faragher