She was officially named to the Finnish roster for the 2020 IIHF Women's World Championship on 4 March 2020, before the tournament was cancelled on 7 March 2020 due to public health concerns related to the COVID-19 pandemic. The 2020 World Championship would have been Karjalainen's debut with the Finnish national team at an IIHF-organized international tournament; she appeared on the national roster for various Euro Hockey Tour tournaments, first in 2016.
