Looking for my sister:Female Born Dec. 1978 in Milwaukee, WI

My Mother had three children, My brother Dale James Jr., born July 26th 1976, Bobbi Jean James (me), born Oct. 1977, and My sister, born Dec, 1978--Her birth name was Carmie Lalita James. My mother, Beverly James (maiden name Urban), gave my sister up for adoption three days after she brought her home from the hospital. She is my full-blooded sister, she was adopted through social services in Milwaukee, WI. I doubt if she kept her birth name. She was born on either Dec. 21, or Dec. 23, 1978--I am unsure. She was born at Milwaukee County General Hospital. Our birth fathers name is Dale Leroy James, he is Native American and African American. Our birth mothers name is Beverly Jean James (Urban), she is German and Polish. Ever since my mother told me about her, I desperately wanted to locate her. I do not even know where to begin. Wherever she is, I'm sure she knows she is adopted, but then again I could be wrong. I pray to the dear Lord that I find her. Please reply to this thread if you have any info or suggestions. I am leaving a picture of me and my brother just in case she is searching, because I am sure we resemble each other. --Thanks