where would they get them from - divine revelation ?
Many of the Mormon 'patron submitted' entries are guesses - sometimes there may be additional family info to flesh out the lack of parish/civil records but rare - can you find your family in the 1851, or a possible burial(s) - I presume we are talking about John gawne + elizth caine - only one child - James - that I can see - the usual reason for singleton children are either a very late marriage or early death (usually childbed) of the mother