Her projects include the untraditional string trio Tríó Sól and the newly formed Spönn collective. Since 2025 Þórhildur also has been a part of Feluleikur, a concert series which hosts concerts in unconventional/abandoned places in Reykjavik. She has performed as a soloist with the Iceland Symphony Orchestra and regularly plays as an assistant with the same orchestra.
Þórhildur studied at the Royal Danish Academy of Music with Asbjørn Nørgaard, Tim Frederiksen and Lars Anders Tomter and at KASK & Conservatorium in Ghent, Belgium with Diederik Suys.