I've had a lot of my Christian friends/colleagues etc say that they don't really think that Mary mother of Jesus (May Peace Be Upon Them both) was actually a virgin. How could she be when she just gave birth to a baby boy.
Well without getting carried away into a very long answer Allah says in the Quran. That if he can make Adam from nothing, no mother and father. It is not hard for him to make Jesus (May Peace Be Upon Him) from just a mother alone.
For if he wishes for a matter to be, he simply tells it to "be" and it is. The Quran has an entire chapter dedicated to the divine birth of Jesus and An entire chapter about the Family of Mary in order to defend her honour.