According to the History of the Girty's and several other sources including family recollection of Simon and Thomas' children and grandchildren, John Turner, Mary (Newton) (Girty) Turner, Simon, James, Thomas, and George Girty were taken captive in 1756. John Turner was killed by the Indians. Thomas Girty eescaped early on when Fort Granville was burned and Simon and probably the rest among the Indians for a "considerable time" according to Simon himself.
I have the old interviews and letters of family members if you are interested.
John Turner married, but never had children of his own.