The William Kelly I'm looking for was married at K.M. January 1768 to Cath Cannell. Likeley his Will 1815, mentions wife Catherine and children. He names sons...but no Robert...my ancestor. Will also names daughters that are not on web sites...only true way is to look at Par Reg.
However there is a christening of Robert Kelley, Jan 1774, in Braddan...names both parents as William Kelly and Catherine Cannell...so looks very promising.