Female born 1956 Napier NZ

We are searching for our female cousin born in Napier NZ in 1956. Her birth is registered as Kathryn Lynda Fisher (birth father's surname) and Kathryn Lynda Burlace (birth mother's surname). "Kathryn" tried to make contact with her birth mother approx. 2000-2001 but her half sister hung the phone up on her! Would anyone having any information please make contact with us.