Amma is a shield-maiden who joined Bjorn 'Ironside' and King Harald's raiding party to return to Kattegat and dethrone Ivar. During the trip across the Baltic, she was asked to watch over Magnus. During the massive storm ride, she overheard Magnus praying in fear to God, not Odin, and questioned him about it. Magnus denied to her that he was a Christian.
In Season 6, she is shown to be fond of Hvitserk and is seen as the care taker of Hvitserk when he was drunk due to the loss of Thora .