Hi Dianne
I am a direct descendant of George and Charlotte in Australia. We were always told we were of Cornish descent but all my enquiries show George and Charlotte came from Alwalton and came to Aust in 1855. His parents were Elizabeth Elms and William who were married at Water Newton and lived at Alwalton. From my research I believe Hannah may have died and Emma married and lived at Longthorpe.
I have been unable to locate where William was born but both Charles and George had Yaxley as the area they came from on the passenger list.
Charlotte was the second child of Mantle in his second marriage as someone has already stated.
Cheers
david