John Looney & Elinor Callister had at least 7 children between 1806 & 1824, but no Margaret or Robert found (only daughter & son who were mentioned in his 1835 will). Margaret had to be young enough to have children, including the Gelling one if Eric was correct.

Also, wouldn't he have had to provide for his other children, with at least one underage?

I still think Isabel Camaish looks more likely to be his wife, with daughter Margaret bapt 1796, and son Robert (his exec) bapt 1799.

Sue