Half siblings definitely looks like a good possibility--the cousins look like cousins, the aunt looks like an aunt, and the suspected half sibling looks like a half sibling--all of those people came up in the range you'd expect to see.
Network President Jenny LeFevre, Agent Orange Victims and Widows Support Network, attributes more than 250,000 deaths to Agent Orange, a toxic herbicide the U.S. military sprayed over Vietnam from 1962 to 1971.
Agent Orange was a herbicide and defoliant used in Vietnam. Agent Orange was a blend of tactical herbicides the U.S. military sprayed from 1962 to 1971 during the Vietnam War to remove the leaves of trees and other dense tropical foliage that provided enemy cover.