I believe that the Gawne family you have listed above,re John 24,Jane26,and Susan1 are a family which has similar names ,but not ours.....:o)
Our Jane(Radcliffe)Gawne was born in 1814,which would make her 36 yrs old in 1850, Her husbands, first name according to Emma's death certificate(1937) lists the father of the deceased as William Gawne, I noticed a William listed as an immigrant to the U.S about 1826..He was listed as a tailor...(on passenger lists)
Jane is confirmed as being Emma's mother,re the IoM census for 1871 where both she and Emma are listed as living with her parents. Janes age is given as 57 and Emma's as 17.Confirming once again the age of Jane at Emma's birth as being 40.....The mystery lies in the extreme age of Jane (35, and 40 ) at the birth of Susan and Emma.
William perhaps was born in the period surrounding 1803-1810.
I hope this saves you some blind alleys....