think I've found John's dau Ann with the other grandparents in 1851 - look at household of Philip Corkill + wife Ann Kelly (a stone breaker at Ballacraine which is just down road from Greeba) - there is an 8 yr old gdau Ann and Philip's eldest son was John bapt Ger 18120913 who might just match the 33 yr old John bur Ger 18470211(?should be 35 for a true match)

that would suggest that both parents John + Ann are dead unless Ann has gone off with a new husband - there is an Ann Corkill m a James Kallary in Marown in Nov 1847 -