Praise be to Allah.
We put this question to Shaykh Muhammad ibn Saalih al-‘Uthaymeen, may Allaah preserve him, who answered as follows:
There is nothing wrong with her staying, if she is sure that she will be safe (from falling into sin), because this is her country now and she is living there. She is not a traveller now. Perhaps she will find a new husband soon and get married. And Allaah knows best.