Welcome to the Search and Reunion Message Board!
Gregory Wiggins evidently was not born in California so the birth parents must have moved to California sometime after his birth but before Melinda was born. Have you also checked classmates.com to see if you can find an email address listing for Lakewood High School for either Gregory or Melinda?
California Search Website:
Other great websites to check out:
http://www.adoptionchat.com
http://www.adoptionlists.com
http://www.adoption.com
http://www.adopting.org
http://www.adoptionregistry.com