Half sister K Kirk of CA. my birth name is Powell/Kishmer O.C. February 4th, 1964?

My birth mothers last name was Powell and maiden name was Kishmer. I was born at Santa Ana Community Hospital in Orange County, Ca. February 4, 1964. I have a half sister that was looking for me but I don't know how to find her ***believe my birth mothers maiden name was Betty Kishmer and she attended Anaheim High School 1940*** Does anybody know any of these names or family members?? Please help me in my search. Thank You