But they had no child, because Elizabeth was barren, and they both were well advanced in years.

 Mary was betrothed to Joseph. Betrothal lasted for a year and was quite as binding as marriage. It could be dissolved only by divorce. Should the man to whom a girl was betrothed die, in the eyes of the law she was a widow. In the law there occurs the strange-sounding phrase, "a virgin who is a widow." 