Elizabeth - too stubborn to do her duty?

Elizabeth I knew her duty was to be loyal to England, marry and bear children to become heirs to the throne and provide security for England for generations to come. Elizabeth was a bright, educated young woman who knew the trouble that had been caused by her fathers struggles to produce a solid heir, her brothers early death without an heir and her sisters phantom pregnancy. While she is often praised for her defiance against convention and her selfless act of not marrying in order to maintain religious stability in England, was she actually more selfish by not fulfilling her duty?

Instead of accepting that she may need to marry a man who was not to her entire liking and bear his children she chose her own, controversial lifestyle.

Was it wrong of Elizabeth to back away from a marital decision? Should she have chosen either a French or Spanish suitor and born his children? Or a wealthy Englishman? Neither choice would have been loved by all but once a solid heir was produced any concern about the future may have eased their worry of the suitability of her husband.

What do you think....selfless act of defiance against convention or too selfish to do her duty?