She started her senior team career with Stjarnan in 2020 and went on to average 16.5 points, 5.7 rebounds and 3.3 assists.
[2] On 24 September 2021, at the age of 15, she became the youngest Icelandic player to play and score in a continental competition when she scored in a win against Clube União Sportiva in the 2021–22 EuroCup Women qualifiers, breaking the records of Unnur Tara Jónsdóttir and Ragna Margrét Brynjarsdóttir.
During the 2021 Nordic U-16 Championships, she registered 10 steals along with a team high 16 points in a win against Denmark U-16.
[6] She debuted with the Iceland national team in November 2023 against Turkey.
[7] Jana is the daughter of former basketball players Margrét Sturlaugsdóttir and Falur Harðarson.