Annafrid or Frida, the non-blonde with Abba with the slightly lower voice, is actually Norwegian. She was born daughter to a German soldier and a Norwegian mother. Come the liberation of Norway in 45, her mother took her with her to neutral Sweden where German soldier offspring was less unpopular than in her native Norway where a lot of women in the same situation were forced to give up their children to Norwegian state children homes as they were perceived as "unfit to raise a child".
Decades later, she would actially get to know her father on a tour in Germany.