In 2013 Themann declared for Scotland. She was eligible to play for Scotland because her father was Scottish. In April 2014 she made her debut for Scotland during a home series against Trinidad and Tobago. She subsequently represented Scotland at the 2014 and 2018 Commonwealth Games and at the 2015 Netball World Cup. She helped Scotland qualify for the 2019 Netball World Cup but missed the tournament itself because of pregnancy.