Girls' Junior (1978) and U.S. Women's Amateur Public Links (1979 and 1980), and was the first female to hold two USGA titles at the same time, joining only Chick Evans, Bobby Jones and Jack Nicklaus.

[3] Her four brothers all play golf professionally, Joey is a Hawaii State Junior champion, Michael was president of the Aloha Section PGA, Ron Jr. was the 1998 Aloha Section Match Play champion, and Rick head pro at the Wailea Golf Club on Maui.

After graduating from Kaiser High School in Hawaii Kai, Castillo attended the University of Tulsa, where she was a member of the team that won the 1980 AIAW National Championship title.

[7] Castillo scored 2-1-0 as a member of the 1980 Curtis Cup team that won at St Pierre Golf & Country Club in Chepstow, Wales.

After failing to obtain her 1984 LPGA Tour card at Q-School, she went to Europe, where she and five other American players were sponsored by a Swiss watch company.