Complex sentence: When the Germans occupied France, she returned to the United States in 1941 on a newly issued American passport but remained only briefly, soon departing for Cuba where she met her second husband, Archibald Burns, a Mexican national of Scottish parents.
Split into simpler sentences: When the Germans occupied France, she returned to the United States in 1941 on a newly issued United States passport. She remained only briefly and entered Cuba where she met her second husband, Archibald Burns, a Mexican national of Scottish parents.