George Girty Jr. was not actually Jack Girty's father. George Jr. was born about 1780 and was possibly married twice. He would be too young to be Jack's father. His second wife was Elizabeth Lynn who was born in 1800. They lived at Zanesville, Ohio until about 1845 then moved to Cincinnati where he died about 1867. I have the exact dates for their deaths, but its not handy at the moment. Both he and his wife are buried in Cincinnati. The descendants of George Jr. lived in the Cincinnati area and Fort Thomas, KY area. Exactly who Jack's father is not known.
There were two Girtys who sold their homes to the government in 1828 in Arkansas. John "Jack" Girty and Isaac Girty were their names. By the early 1830s they both lived in Oklahoma and appeared in the Thompson trading post ledger. Also listed was a Simon Girty. Simon and/or Isaac Girty's family remained in the Illinois District and left many descendants. There was a Simon Girty that was born "east of the Mississippi" in 1829 and his descendants are known. He was a son of either Isaac Girty or Simon Girty.
Simon Girty (b.1829) was listed in the old Cherokee rolls as a "half breed" so he could possibly be connected to the famous Girty brothers. The only known or proven Indian children are the children of James Girty who were James Jr. and Nancy.
George Girty had a son George Jr. who seems to have settled into white society and a daughter who married George Morgan White Eyes, the son of Chief White Eyes. Her name is not known and as I said before, George Jr. settled in Zanesville, Ohio. There were two other Girtys nearby, one named Amanda Girty (b. ca.1790s) and a Catherine Girty who was born about 1774. I don't know there connection. Catherine seems to have been a widow or never married. She died in the 1850s.
Simon Girty was known to have one son named Simo-ne or Ked-zaw-saw Girty. He appernetly settled near Aurora, Indiana and changed his name to Simon Peters. An old narrative from a man who knew him stated that this Simon Peters was a son of Simon Girty. Then there was a half-Indian named Michael Girty who settled in Illinois, who was known as a "terror" during the Black Hawk war. He is said to be the son of Simon Girty, but this was probably a supposition do to the history of old Simon. Michael died in the 1830s.
Now as far as the Oklahoma Simon, Jack and Isaac go its hard top tell if there is a connection. The proof linking them just isn't there. Considering Jack's birth of about 1792 he could have been George Sr.'s son, or the family may just have taken that name for some reason. The fact that Simon (b. 1829) was listed as a "half-breed" and the statments of Jack's grandchildren stating that they were possibly of Irish descent is compelling evidence but not proof enough. Still looking for that smoking gun.
I do have a photograph of Wilson Girty that Bob Neely sent me. I can send you a scan in an e-mail. It will have to wait until after the holidays since I'm traveling at the moment.
Lastly the national archives has copies of the Civil War pension files of Wilson Girty, Snake Girty and I think Stud Girty (Wilson's brother). I hope this helps.