。
Is she married?
Literal
She [topic-は] is-married [question-か]?
A polite yes/no question built on resulting-state ~ている: 結婚している reads as a stative ('is married'), not a progressive ('is currently marrying'), so 結婚していますか asks whether the person is in the state of being married. The sentence-final か turns the polite-form predicate into a question; modern writing usually adds a question mark too, though classically just か was enough. This is one of the most everyday questions in introductory Japanese curricula.