The only Swann I have is
Swann Rev. Sidney, M.A., curate in chage,The Vicarage, Sulby in 1889 - possibly a little
(btw the Vannin = genitive of Mannin (manx for IoM is Ellan vannin so guess you have an educated parent) - there is a window in St Stephens dedicated Sydney Ernest Swan born St John Baptist’s Day, 1890.

around the 1850's/'60 there was a Swan family in Patrick - John Sauders Swan + Emma Looney - Major Robert Swan Stephen was connected to this family but they appear to be missing from 1851 census

The 1861 census has a Swan family in Douglas - probably Widow Julia Elizabeth + children - English except for 2 children Ireland + Scotland