Pure conjecture here, but Sarah probably came >from England too. Can
you find a marriage certificate for Hart and Sarah that would give
more information about her background, such as maiden name, parents,
age, etc.? Or perhaps her death certificate which often contains
these same elements?
Can you find Moses Philips on a census record prior to transport? That
might give you more information about his English family.
Best of luck.
I have recently discovered a 4xgreat grandfather who was a Jewish convict
sent to Tasmania (van Dieman's Land) >from London in 1820. Very exciting -
the first Jewish person and first convict in my very English family tree!!
His name was Moses Phillips and he married another convict soon after his
arrival in Tasmania and went on to produce a large family.