After eight seasons at the IcelandicÚrvalsdeild kvenna with Breiðablik, where she scored 50 goals in 107 league matches, Fanndís decided to join NorwegianToppserien club Kolbotn, signing a year contract on 6 December 2012.[5] Ahead of her second season in Norway, she moved from Kolbotn to Arna-Bjørnar in December 2013.[6][7]
On 15 May 2014, Fanndís was released from her contract by Arna-Bjørnar after requesting a move back to Iceland to play for Breiðablik.[8] As the request happened during Icelandic's last players transfer registration day, it was only confirmed on the following day (16 May 2014), that Fanndís was successfully registered as a Breiðablik player, her second spell at the club.[9]
At the end of the 2017 season, after four seasons of her second spell at Breiðablik, she had a combined total (both spells) of 104 goals scored in 197 matches in all Icelandic domestic competitions, of which 97 goals were scored in 173 league matches.[10]
On 27 June 2018, Fanndís signed with Úrvalsdeild kvenna club Valur.[15] In September 2018, she was loaned to Adelaide United of the Australian W-League. She scored 2 goals in 11 matches for the club, witch finished 6th in the league, 1 point out of the playoffs.[16]
International career
Fanndís has represented Iceland since 2005, initially at the under 17 team, progressing to the under 19 and eventually arriving at the senior team in 2009, making her senior international debut on 9 March 2009 in a 2–0 defeat by Denmark at the 2009 Algarve Cup.[17]
A few months later she was called up to be part of Iceland squad at the UEFA Women's Euro 2009, where she made two brief substitute appearances as Iceland were eliminated in the first round.[18]
After playing the 2015 Algarve Cup and 2016 Algarve Cup, Fanndís scored again during the UEFA Women's Euro 2017 qualification matches, with her first brace (two goals in one match) for Iceland on 7 June 2016 in an 8–0 win over Macedonia and one more goal came on 20 September 2016 in a 2–1 defeat by Scotland, taking her tally to eight goals.[19] Her ninth and tenth were scored at the 2016 Sincere Cup, on 20 October 2016 in a 2–2 draw with China and on 24 October 2016 in a 1–0 win over Uzbekistan.[19]