Here is a link that matches your DOB/State:
Jan 18 1958, Ca, Find Birthmother, Birthfather, Birthfamily, Birthson, Birthdaughter, Adoption Recor
Biological Mothers name, Eileen Mcr A Miller Adoptive Parents names, Fred and d M McLeod My Addresse Darlene Mch Church RR 4 Site 120 omp. 20 NoN Bay, ON P1B 85
You could look into High Schools in the area. Find their reunion page & start asking if anyone knew of a family with 8 siblings. If she was 14 in 1958 she may have likely been due to graduate in say 1962. She had to be friends with someone in that class.