Thanks very much for all this- you are amazing! I did note the large age gap between George and his wife Mary, which as you say seems to fit with the family legend of the family friend marrying the woman he had known from when she was a small girl. Assuming that his wife was Mary Watson (and that 1833 marriage does seem likely given the children's birthdates), I have found a Mary Watson bapt. at St Lawrence Anglican Church, Heanor, Derbyshire, on 2 September 1807, which could fit. Her parents are given as Thomas & Hannah Watson. An Anglican baptism, though, probably puts paid to my guess that her parents' group of philanthropic friends might have in fact have been Friends (Quakers) .
Another snippet from the family history says that my grandmother's grandmother, Martha, nearly didn't make it off the ship. She gave birth on board the ""Cartvale" and had such a difficult delivery (the baby was lost) that she was believed to have died as a result. Preparations for a burial at sea were under way when her husband Richard noticed one of her hands give a tiny twitch. She was revived and went on have another five children in New Zealand!