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.
Not until 1995 did Vietnam release its official estimate of war dead: as many as 2 million civilians on both sides and some 1.1 million North Vietnamese and Viet Cong fighters. The U.S. military has estimated that between 200,000 and 250,000 South Vietnamese soldiers died in the war. In 1982 the Vietnam Veterans Memorial was dedicated in Washington, D.C., inscribed with the names of 57,939 members of U.S. armed forces who had died or were missing as a result of the war. Over the following years, additions to the list have brought the total past 58,200.