Unsure Where to Start (searching for half-sister)

Hello,My mother had a little girl on Feb 14, 1972 at the Salvation Army home for unwed mothers in Sand Springs, OK. Mom's family made her give her up for adoption and she never even saw her. She talked about her every so often and expressed a desire to find her -- but she didn't get very far. This adoption.com profile wasn't even fully activated. She was afraid of being rejected, I think.Sadly, Mom passed away in March. I'd love to try and find her daughter, if she was willing, and talk to her. How would I go about this?Thank you.FYI - this is what Mom had written down:I am looking for my daughter. She was born February 14, 1972 in Sand Springs, OK at the Salvation Army home for unwed mothers. I was told the birth mother would be listed as Sally Gritz. My name is Violet (Grim) Martin. The adoption was kept secret from me, but I had to go into Tulsa County to sign papers, so I am assuming the adoption was handled by the state from that location.