Looking more closely at Dorothy's will which was written in 1747, this is John's quitclaim:

"Oct 24 1751 John Ellison son of the within testatrix acknowledges upon
the receipt of 2 4d from his father Silvester Ellison to be fully paid and
satisfyed for all legacies bequeathed him or his wife by his said mother
and acquits him and his exors forever for the same and the said Silvester
Ellison relinguishes all demands he has on his said son John for any
goods or accounts relative to said executorship"

The " his said wife" refers to:

"She left and bequeathed to Cathrine Ellison the stuff for a gown."

So John's wife was called Catherine. Another clue ?