searching for 1/2 sister PLEASE READ!!!

My mother gave a child up for adoption when she was 17. My grandmother was very strict in her days and over ruled all of my mother needs and wants. So the choice for adopting out her baby was not my moms choice. Sometime during December of 1966 or 1967 my mother gave birth to a child, she was not able to touch or even see her baby in the hospital. To make things worse my grandmother and grandfather, along with my mother drove the baby home. With the child in my grandmothers arms the entire way, from Washington to Oregon, my mother was only allowed to sit in the back seat of a three row van and face towards the back window. Before they got home, the doctor that had delivered the baby already lined up the adoption. And the baby was delivered to a private office. And that was the last memory for my mother. Because of this tragedy in her life, my mother has suffered a severe clinical depression, and was actually hospitalized for two years. And still my mother never had a chance to heal. My mom was told that she had given birth to a healthy boy and she never had reason to question otherwise until my sister and I decided to contact Oregon Department of Family Services to help in our search. At that time the only official information they would give us was that my mother had given birth not to a boy but actually a girl, so for 35 years my mom was searching for someone who never existed. I have some information about this child but from what I understand, information can be forged so birth years can even be off. I know she was born in Washington, (tacoma area I believe) My mom is not to healthy anymore and I pray for her that if I can do one thing for her before she is gone, it would be to find her baby girl, so she can finally heal. Please help me, I will take anything I can get Sincerely, Stacey