there is child named Ann with mother Isabel Sayle baptised at Patrick on 13th March 1799 - no father named in parish register nor can I find her mentioned in the presentments for fornication (look up these on www.manxnotebook.com).

The 13 children with last child bapt in 1841 supports a very young bride - there should be a note in the parish register as to whom gave permission at the marriage - I looked at the register some years ago (it was then in very poor condition) but only noted the two witnesses John Kelly + Robt Oates.
Lookup www.imuseum.im