Owing to lack of time for research in Portsea, only four entries in the name of Elizabeth Mitchell were traced:
(1)  Elizabeth Mitchell married Thomas in 1788.
(2)     Elizabeth Mitchell of Sandwich Terrace died on 21.3.1813
(3)     The birth of a son, David, to James and Elizabeth Mitchell on             21.5.1775.
(4)  In addition to these three and the wedding of Richard Freemantle and Elizabeth Mitchell, there was the record of a marriage (page 79) on 29.10.1779 witnessed by a Benjamin Freemantle.
What we do know from these records is that this Richard Freemantle was married to (1st) Elizabeth Mitchell on 1st.November 1795 in that church, or rather the original church that stood upon the same site as the present one.  In fact, there have been three churches, all called St. Mary's, the first being built in the early twelfth century and that was only replaced in 1843 and, even then, the original tower was retained.  The 'modern' church, that is the third one on that site, was consecrated on 10th.October, 1889.  It is known that the original church was in existence in 1170, a year in which the Bishop of Winchester happened to be William the Conqueror's grandson.
"Up until the eighteenth Century St. Mary's was a village church, outside the walls of the city of Portsmith, and in the midst of a community living by agriculture and fishing.  There is evidence in the figures of the Parish Register that this community was very small.  In 1666, for example, there were only five marriages in the parish, possibly following the depredations of the plague.  By 1701 there were 56.  During the years, around the turn of the 17th century into the 18th, Portsmith grew rapidly and by the middle of the 19th century the spread of the Industrial Revolution had turned Portsea Island from a rural area into a densely populated and fast growing naval port.
Up to 1843 St. Mary's church remained as it had been in the 12th century.  It was a low, short building with a red tiled roof set with dormer windows.  At the west end was a square tower, and inside was a gallery, (which had been added after the church was built together with the tower) and uncomfortable high box pews, with flaps for the poor on their doors.  There was a screen separating the chancel from the main body of the church, and a three-decker pulpit surmounted by the figure of an angel with a trumpet.  The roof was supported with rough cross beams."
Elizabeth Freemantle nee Mitchell died somewhere between 1809, when their third child was born and 1814, [probably nearer the later date] leaving her husband and three sons, Richard, John and Samuel.  
Richard remarried and family tradition has it that this marriage was to his housekeeper, Sarah Kent, who was born in about 1789.
[Source IGI No:912 gives Richard's (2nd) marriage (to Sara Kent) as in 1814 in London]
In 'Some Frontier Families' the authors claimed Richard was the son of a wealthy London gentleman.  Because a good number of Freemantles lived and were long time residents in and around the Southampton area, this and his marriage into the local Mitchell family leads one to doubt the London connection, but tradition has it that the second marriage so enraged his father that Richard was disinherited and the couple moved to London, where their two children, Eliza and George were born in 1815 and 1818 respectively.