Aside from the answers given here, you can also phrase your text to reflect this in the bio, depending on the person. In this case, it's easier to say "Noreen never married," because she is a notable. But in cases where the information is more sparse, you can use more general text such as, "It is not currently known if Noreen ever married," or "It does not appear as though Noreen ever married", especially if you suspect a source could be found later.