DaveKing, it is interesting that William Lowther's daughter,Sarah, died at Sorrento in 1928, but you may have already known that.

EventDeath Event registration number3664 Registration year1928
Personal information
Family nameWILLIAMS Given namesSarah Jane SexFemale Father's nameLOWTHER William Mother's nameEliza (Unknown) Place of birth Place of deathSORRENTO Age69

William Lowther might have been still living in the same place before and after 1861. The place of birth would be more accurately described as PLACE OF REGISTRATION OF BIRTH. The Pt Nepean births up to 1858 that you mention would have been registered at the Sanitary or Quarantine Station at Point Nepean and the Tootgarook registrations would have followed the declaration of a township at Rye in 1861 and the appointment of a postmaster and registrar for the town (the same person usually filling both roles.) Towns were usually surveyed well before they were declared and the site of this village reserve was probably part of the Tootgarook run with the result that Rye was known as Tootgarook for some years. Sorrento was not originally surveyed as a town site and it was not until Charles Gavan Duffy and William Allison Blair were having a barney about selections in the latter 1860's that Sidney Smith Crispo (as he claimed in 1899)suggested that a disputed selection should become a village. It did and blocks sold like hot cakes which did wonders for Crispo's private village of Manners-Sutton/ Canterbury (both names honouring Sir John Manners-Sutton who became Viscount Canterbury during his term as Governor.) It may well have been in this village on the west side of Canterbury Jetty Rd that William Lowther bought his block. Edward Williams who became a great friend of Crispo's was said to have looked after Crispo's grant at Canterbury before selecting land straddling Browns Rd just east of Truemans Rd. It is possible that his son Edward, known as Ted, married Sarah Lowther but I'll have to look into this. Ted's mother's maiden name was Mary Campbell; she came out in 1852 with Robert and Mary Cairns and her husband arrived on a survey ship in 1855. They met at the Burrell's Arthurs Seat homestead where Mary found work as a servant.

Dave can you send me a private message so we can exchange contact details?
I will copy your information and request for more information onto the HISTORY OF DROMANA TO PORTSEA Facebook group page where Linda Berndt of the Rye Historical Society and Clive Smith of the Nepean Historical Society may be able to help.

You could join the HISTORY OF DROMANA TO PORTSEA group to converse directly with any members who respond.

Edward Williams married Mary Campbell in 1855.
EventMarriage Event registration number1263 Registration year1855
Personal information
Family nameWILLIAMS Given namesEdward SexMale Spouse's family nameCAMPBELL Spouse's given namesMary

Their son Jimmy the Squid Williams was born in about 1858.
EventDeath Event registration number20370 Registration year1947
Personal information
Family nameWILLIAMS Given namesJames Campbell SexMale Father's nameWILLIAMS Edward Mother's nameMary (Campbell) Place of birthRYE Place of deathDROMANA Age89

Jimmy and Ted died on consecutive days, the latter at the heritage listed Eastbourne homestead in William (sic) Crescent.
EventDeath Event registration number20369 Registration year1947
Personal information
Family nameWILLIAMS Given namesEdward Thomas SexMale Father's nameWILLIAMS Edward Mother's nameMary (Cambell) Place of birthRYE Place of deathROSEBUD WEST Age91

Ted is buried in an unmarked grave at Rye cemetery on the left side of the main path just before it ascends, between the graves of Cassie Williams and Jimmy Williams and opposite the grave of Sidney Smith Crispo. Linda Berndt knows why Ted's grave is not marked.

Ted was born in about 1856 so he would have been about 27 in 1883 and could well be the Edward Williams who married Sarah Lowther in 1883. THERE WAS NO MARRIED NOTICE TO CONFIRM THIS.

A SLIGHT CORRECTION. CASSIE'S GRAVE SEPARATED THOSE OF HER BROTHERS TO PREVENT THEM QUARRELING IN THE AFTERLIFE!
Ted is buried in an unmarked grave at Rye cemetery on the left side of the main path just before it ascends, his grave and Jimmy's separated by the grave of Cassie Williams and opposite the grave of Sidney Smith Crispo. Linda Berndt knows why Ted's grave is not marked.