Looking for data on birth mother (she was born between '35-'37 and lived in St Louis)

Hello, I was born in Ohio on 3/11/1961 and adopted in 1962. I have my original birth certificate and a few other docs surrounding my adoption. I have contacted the agency that handled my adoption and did get some facts assisting my search, but I have a lot of holes on my birth mother's side. I have located my birth father and have confirmation he is my father from the welfare agency that handled my adoption. I have traced my paternal side back several generations already. I have my birth mother's maiden name, but NOT her birth date. She reported to the agency that she was born in St. Louis, and I believe she was also married and divorced in the St. Louis area before going to Ohio. She gave birth to a son (my half brother) ~ 1953 (again in the St. Louis area). She had to have been about 17 years old then. Her name is (was) Patricia Jean Lane. She was 25 years old on 3/11/1961 when I was born. This would put her birth years between 1935-1937. I am trying to find anything I can out about her. I'm told she may show up on birth, marriage and divorce decree paperwork in St. Louis. Can anyone help? Thanks!!!