William S Bragg/Bernetta Bragg 1900s ILL

I am the oldest of 4 children born to William Stephenson Bragg and Bernetta Bragg, nee Vrell. We were all adopted out when I was about 6. I was born Richard Dean Bragg on August 14, 1960 in Moline, Rock Island County, ILLINOIS. I have found my younger brother Lester and 1 sisters Stephenie. I am still looking for our yougest sister Willa and our parents.
I have not been able to track them down to find out what happened. Any information would be extremly apreciated.Thanks, Richard Wayne McMorran