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.
The chemical was Agent Orange, the occasion was the war in Vietnam, the time was 1961-71, and the country was South Vietnam. Some 12 million gallons of this supercharged weed killer, enough to douse 18,000 square miles, were sprayed on the 66,000 square miles of South Vietnam during the War.