Hi Mary, John Carrier married Elizabeth White on August 29, 1724. We have proof of this in the Bruton Parish records. He did not marry Jemima Nicholas until 1756. This means that the following children were of Elizabeth White and not Jemima Nicholas: 1) W. John Carrier Jr. (born 1728) 2) Henry Carrier (born 1730) 3) Thomas Carrier (born 1732) There are rumors that W. John Sr. and Elizabeth White had other children that did not immigrate to America, but I have no proof of this.
W. John Sr. and Jemima Nicholas had at least five children together that I know about.
As for the "W" in W. John Carrier, I am unsure as to what it might mean. I thought perhaps "William", but this is usually signified as "Wm". It is interesting to note that in the marriage records of Bruton Parish, the "W" is not present. The record is listed as John Carrier & Elizabeth White.
Perhaps the "W" stands for some sort of title? Note also that John Jr. as the eldest son also bears the "W", possibly signifying an inherited title. This, of course, is pure conjecture. I have also been very curios as to what the "W" stands for!