Full Filipino heritage people have a distinctive facial feature that some of them are proud of that gives them a separate look from other Asian/Pacific Islanders.
The girl on the dock definitely has this feature. The one at the gathering is not obvious.
The McKoen 1964 INS letter referencing ‘...USC wife, who is in the Philippines...’ shows that may very well be this woman.
What distinctive facial feature do you refer to? I lived in HI for many years plus have many Filipino friends so I’m wondering what you mean in particular.