During my research I have found the name Petty spelled Pettey, Petey, Pettie - sometimes these different spellings have occured within the same family. This happened before ordinary working class people learned to read and write. Therefore when people gave their names to officials, at the time of birth registering, marriage and census, it was dependant upon the official writing the name as to which spelling of the name he chose to write down.

This is my tree:

John Petty c1715 born Tredington Warwickshire England married Ann Stephens c 1715 born Tredington.
Tredington is a village near to Stratford upon Avon.
They had at least 5 children: John Petty 1739, Mary Petty 1741, Thomas Petty 1743, Joseph 1746, Elizabeth 1748 - all born Tredington Warwickshire.
My line descends from Joseph 1746. He married Elizabeth but no more is known about this lady.
They had at least 4 children: Thomas 1774, Joseph 1776, William c1779 - 1859, Sarah Petty 1779 all born in Tredington.
My line continues from William c1779 - 1859 he married a lady named Ann c1775-1840 her surname is either Pardoe or Parker. They had at least 9 children who were all born in the village of Quinton, both Lower and Upper, which has at some time been in both the county of Warwickshire and Gloucestershire. Again these villages are near to Stratford upon Avon.
Please don't hesitate to contact me - jeangrice@yahoo.com