I think Edward Clague was consistently recorded as b.1879/1880, inclu. aged 26 at the Maughold marriage I posted several years ago. He was from Patrick then, with his father given as Edward Clague, labourer (please note: father "deceased" in 1906). Had you looked into the possibility that he was an illegitimate child of one of the Kelly daughters with whom he was living in the 1881 census? It was usual for an illegitimate child in the IoM to be known by his father's surname. I can't see a possible Edward anywhere else in 1881, and his place of birth was simply ditto marks amongst others below a list of Douglas, so could have been an error. Incidentally, I think the widowed Eleanor Kelly's age was 51, not 56 as given on FamilySearch.

The IGI has an extracted birth entry for Edward son of Isabella Kelly on 8 Sept 1879 Peel. I know Peel isn't Patrick, but it is close! She could have been living in Patrick but gone to Peel for the birth? Or to register the birth? This entry was also on Brian Lawson's birth regt index: Edward KELLY 8 Sep 1879 Peel [father] Not given, [mother] Isabella KELLY.

I looked for the youngest child in the 1881 census entry: [IGI] Agnes Elizabeth Margaret KELLY Christening: 10 OCT 1869 Saint Barnabas, Douglas Father: THOMAS KELLY, Mother: ELEANOR.
Elizabeth aged 19 in 1881, bapt 30 MAR 1862 Saint Mathews, Douglas, same parents.
I couldn't see an Isabella, but Elizabeth and Isabella were names which were sometimes used interchangeably, so Elizabeth Kelly is a possibility to have been Edward Clague's mother.
BL's birth regts also have:
Lily KELLY 26 Sep 1883 Ger., [father] Not given, [mother] Elizabeth KELLY.

Sue