Icelandic women's last name is based on their fathers first name.
For example if the woman's father is named Thorvald, her last name is Thorvaldsdottir, or if her fathers name is Gunnar, her last name is Gunnarsdottir. Dottir = Daughter.
I was looking at the line-up of Iceland's women for their match against Belgium, and was wondering why they all have dottir at the end of their name. The more you know.