The History of Waterbury, Connecticut by Henry Bronson(1858) gives the information that Millicent Garnsey was married on Dec. 6, 1771 to "Lieut. Osborne" without providing any additional information about him. The Garnsey-Guernsey Genealogy by Eva Garnsey Card and Leslie Ellsworth Card provides the information that Millicent Garnsey's husband was Lieut. Thomas Osborn and that after the Revolution, Thomas Osborn and his family lived for a period of time in Digby, Nova Scotia. Recorded in Digby, NS deed book 1B on pages 8 and 9 is a deed where "Thomas Osborn of the Town of Digby, County of Annapolis & Province of Nova Scotia, Blacksmith" sells property to William McDorman. The deed is signed by both Thomas Osborn and Milisent Osborn, thus verifying the Garnsey-Guernsey genealogy.
Having moved to Nova Scotia after the Revolution, Thomas Osborn was evidently a Loyalist. A Geography and History of the County of Digby, Nova Scotia by Isaiah W. Wilson(1900) provides information on the Loyalists of Digby. Listed in a muster list (probably taken in 1784) on page 71 is "Thomas Osbourn, 8; Jabez Osbourne, 1;". This indicates that there are eight members in Thomas Osbourn's family and that Jabez Osbourne is a single person. As the muster list is not alphabetized, Jabez Osbourne either lives next door to Thomas Osbourn or possibly even lives with Thomas Osbourn. It seems likely that in 1784 Thomas and Millisent Osborn had six children. Their son Jeremiah was not born until 1787 (according to the 1850 census of Jeremiah), so there are at least three children who must have died prior to 1805 (the year of Jonathan Garney's estate distribution) without living issue.
Volume 43 (July 1978) of The Connecticut Historical Society Bulletin has an article "The British Army and the Connecticut Loyalists During the War of Independence, 1775-1783" providing background and some specific information on the Loyalists of Connecticut. As the Revolution began, tories suffered in Connecticut and took refuge to Long Island which was under British control. From the article: "A former blacksmith from New Haven, Thomas Osborn, had gathered in sixty or seventy men under Browne's warrant: he and his brother used their trading schooner to ship 'a great many loyalists' to the British fleet at Staten Island -- '27 or more at one time.'" This would seem to refer to Thomas Osbourn and Jabez Osbourne in the muster list mentioned above. Of the Osborn families living in New Haven, CT at the time, only Jeremiah Osborn-5004 has sons named Thomas and Jabez.