Queen Keran (or Kir-Ann, d.1285) bore her husband Leo II (d.1289) fifteen or sixteen children. By all accounts, she was a loyal and devoted wife. This article on http://enacademic.com/ states:
Many words of praise were made about Queen Keran by her contemporaries. Her son Hethum claimed that "she had a wonderful soul and a beautiful body." The chronicler and scribe Avetis, described her as "a good friend to her husband in trouble and joy."
However, after the birth of her last child in 1283 or 1284, she became a nun at the Drazark monastery (Armenian Apostolic Church). I haven't been able to find any information on this relating to the medieval period.
Were married women able to become nuns in the Armenian Apostolic Church in medieval times?