Thunem swam avidly as an able bodied youth, but gave it up at the age of sixteen as she did not want to sacrifice her social life.

[3] Thunem returned to swimming as part of her rehabilitation program following her first attack, and found that she had a natural ability for the sport.

[2] Initially classified as a S5 disability swimmer, after her condition worsened in 2012 she was re-classified as a S1 competitor, for athletes with the most severe limitations to their natural swimming action.

[4][5] Her achievements at the German Championships saw Thunem named the Female Disability Swimmer of the Year by Swimming World Magazine.

[2] In the buildup to the 2016 Summer Paralympics Thunem appeared at her second European Championships, this time held in Funchal, Madeira.