Kelleghers, Clones, Co. Monaghan

I am trying to find out about an ancestor John Kellegher (or other variants of spelling used) of Gransha/Gransha Beg, Clones. John was the son of Hugh Kellegher, a flax scutcher. John was aged 10 in 1901 and lived in the home of his grandfather Patrick Hand who was aged 60. In 1911 however his parents are listed as being married for 10 years with 1 child so this doesn't add up.

In 1911 Hugh and his wife (Mary aged 45) are listed on the census. According to  family info John joined the Merchant Navy and went to the US (we have his phot and MN info) but we cannot find out any other info about him, his birth or baptism or his family - his father Hugh or any family he may himself have had later on. I am a descendant of his mother Mary.

Thanks in advance for any help

Mrs Doyle