Fact is, there never was (at least on record) a Sarah Southcott, either from Kent or from Devonshire. And as far as anyone can determine, there were no Mulfords (or Molfords) even living in Kent (at the time) when William and John came to America. So the whole Sarah of Maidstone, Kent theory many have heard about really is utter nonsense.
However, it is likely that the name Sarah at some point was a misread of the name Suzan, since the two names do look much alike, especially in old handwritten forms. Which tends to indicate that there was at one time some old handwritten document naming Suzan as the mother of William and John.
Yes, there is on record a Suzan Southcott (b. 1551) who did indeed marry a Thomas Molford in Devonshire on Dec. 3, 1571. See, The Visitations of Devon, 1620, under Southcott of Southcott and Molford of South Molton. In fact this is the only instance on record anywhere of a Southcotte by any name ever having married a Mulford.
Spellings, even of proper names, were not standardized at that time, so royal officials often spelled these names however they pleased. The name Southcott (of which the most correct spelling appears to be Southcotte, from South Cottage) was also spelled Southcot, with a single T at the end, on rare occasion. Similarly the name Molford (of which the most correct or widespread spelling --from earliest times-- was Mulford, with a U) was on rare occasion spelled Molfford, in the Visitations, and even Muleford in some very early documents.
While the name was sometimes confused with Milford, it did not derive from Milford as some have claimed, but rather from Munford (also spelled Moford and Montford), from the De Montfort family (Richard, Simon, Amaury) of Montfort-l'Amaury, Ile de France, near Paris, and not from the Dover, Kent Montforts (Ralph, Hugo, Hugh) of Montfort-Sur-Risle in Normandy. As can be easily proved. They did not come from a town called Mulford or Muleford. Rather, these towns were named after the Mulfords who founded them.
The earliest mentions of Roger Molford (later of South Molton and much too early for him to have received the Mulford Coat of Arms in 1420 as claimed), identify him as Roger de Mulford, with a U, and there is even evidence (see for example, Ancient Long Island Epitaphs, by Edward Doubleday Harris) that early East Hampton Mulfords spelled their name --at least on formal occasion-- as Molford, with an O, just like the Molfords of Devonshire.
And just like the Molfords of Devonshire and Wiltshire, the Mulfords of East Hampton were landed Gentry and Yeoman mostly, being addressed by the then exclusive or limited title, Gentleman, on more than a few occasions. While this alone does not absolutely prove William and John were from Devonshire, it certainly helps to substantiate the claim.
As for there being no William among the children of Thomas and Suzan Southcotte Mulford, authorities apparently have missed or ignored the fact that William in those days was a kind of second name for Gilbert, and vice versa, as evidenced in numerous family documents of the time. According to the Visitations, Thomas and Suzan did have a son named Gilbert, and though he and his brothers are said in the Visitations to have (ALL) died without issue, this is answerable by the simple fact that the brothers left for America immediately after participating in the English civil wars against King Charles the First.
The Southcottes especially were loyal to the Crown, and so any children born to the brothers afterward in America would have remained unknown to their Devonshire kin. The unjust murder of King Charles, and their need to escape retribution for having been in any way a party to it, explains why almost nothing could be said of our origins --until after America had become independent.
This was true not only for William and John, but for the third brother, Thomas, as well, who "went South." Apparently much farther south than Virginia, I suspect, since the Mulfords of Colombia, South America do in fact recall descent from another brother of William and John.
John of course did not die in England. As was discovered by the genealogist Stuart C. Wade more than a century ago, English authorities for whatever reason --possibly even out of nationalist pride-- have confused the disappearance of John in 1610 (curiously given as his date of birth in various American sources) with the death of a related John Molford about the same date some 80 years later.
My 90-year-old father, a direct descendant of William Mulford (my 8th-Great-Grandfather) is in possession of an ancient account detailing our history over nearly a thousand years, which has been passed down father to son at least since the time of Capt. Ezekiel Mulford who seems to have given it its present shape. As children, my siblings and I listened keenly to this account, also told and retold by our grandfather Henry B. Mulford who learned it from his father and grand parents before him.
One especially intriguing detail, which has always stuck with me, is that the brothers, whom we recall as "William and John," came from a family of "medical people," a detail not noted in any historical records of which I am aware but which appears remarkably confirmed in the findings of Stuart C. Wade who observed that the Molford House on South Street in South Molton (which remains to this day a medical establishment) was then still in the possession of a medical man. It would seem that this House, apparently the original residence of Roger Mulford, has been a place of healing of one sort or another in South Molton for centuries.
Another fascinating detail, likely to prove controversial, is that at least one of the brothers is said to have had another wife back in England. I'm guessing that was John, but this may have been true of William, as well, who seems to have married on the American side rather late in life, given that he could not have been born much later than 1595 by my calculations, since his parents married in 1571 and since his mother was born about 1551, according to Bovey Tracey church records as well as the Visitations.
William and John couldn't possibly have been born so late as 1610, let alone 1618 or 1620. Fact is, we really don't know when either of them were born or exactly how old either of them were when they died. I suspect they both lived to be about 90, if not well into their 90's, which has been characteristic of most Mulfords in my family line.
There does appear on record a "William Mulford" born in 1595 --into the house of Roger and Amy-- along with his brother John whose date of birth is unknown, though some say he was born about 1580. In either case, they appear to have been born much too late to have been the actual children of Roger and Amy, especially since Roger is known to have died in 1594. It is likely they simply grew up in the home of their grandparents, and so were counted as part of that household, as well as of the household of Thomas and Suzan.
With the science of genetics improving by leaps and bounds almost every day, it should be possible not long from now to document all of this genetically. It shouldn't be hard at all to prove whether we are Southcotte descendants or not. Genetics holds the answer to all our questions.