Hi Jean,
It is hard to comment on the accuracy of some of the information herein, as you don't give sources. However, you have previously made the comment re: "all the sites I can get into", which leads me to infer that you are not looking at original records, but rather at compiled genealogies on sites such as Ancestral File, World Connect, World Family Tree, ... While these sites can sometimes provide valuable hints for research, the "information" on them much be taken with a very large portion of skepticism, lest you just continue to perpetuate others' errors.
To straighten out the Manx families, you really need to look at the original records: parish registers of baptism, marriage, burial; wills; land records; cemetery inscriptions. The original records are mostly filmed by the LDS church and are available to view at your local Family History Center. In addition, much is available (with sources given) at Frances' Manx Notebook, and at Brian Lawsons' Manx site www.lawsons.ca/
To comment on your above message, the John Skillicorn who married, May 19, 1750, Bessie Fargher, was, indeed, born about 1725. His baptism is given in the Lonan parish records "St. Jo... Day Xmas 1724. He was the son of Thomas Skillicorn and Margaret Clark (who married 1718). This John was buried at Lonan, December 31, 1750 "John of the Mountains". His will is on Brian's site: 1750-2A.
He may possible be the John who married Jane Kewley Jan 31, 1743, but I am not aware of any evidence to support that.
Jane is almost certainly the Jane who was buried Lonan, November 20, 1744. Her will names siblings John, Philip, William, Elinor (John Clague), Margaret (William Kewley), Catherine. It does not name any children. Also does not name her husband, which would tend to support the theory that she was married within the year, and thus he would not inherit.
John Skillicorn and Bessie Fargher had a posthumous son Thomas, baptized March 7, 1751. Bessie did NOT have John b 1752 and Philip b 1757.
Bessie married second, Philip Kinley. Her marriage record has not been located, but her will (1793-2) clearly indicates that she was Elizabeth Kinley als Skillicorn als Fargher, and names her only child Jane Casement als Kinley.