When a woman gets married, she takes on her husband's customs. Thus, an Ashkenazi woman marrying a Sfardi man gets to eat rice on Pesach (and vice versa).
But what happens if she gets divorced, or if her husband dies? Does she continue to follow his customs, or does she revert to her maiden family's?
Does it make a difference if she has kids or not? (I know it does with regards to a Kohein's ex-wife or widow eating trumah.)