ISO Half Sister either 3 years older or younger than me 10/31/77

I found out today that there is a possibility that I have a sister that was possibly given up for adoption by my biological mother. Stated she was either 3 years older or 3 years younger than me. I am a biracial girl born 10/31/77 in Shreveport, LA. Adopted through Volunteers of America. Mother was German and Indian. She only went to the 10th Grade and was around 23 when I was born. She is around 5' 7" and possibly wore glasses with Blonde/Brown hair and blue eyes. Please let me know if you are looking for a half sister as well.