Nielsen was recruited by Greater Western Sydney with pick 60 in the 2018 AFLW national draft and was expected to play as a back-up ruck for Erin McKinnon.[2] Nielsen debuted in round 4 of the 2019 season against Collingwood when McKinnon was a late withdrawal after falling ill.[3] In August 2020, Nielsen retired from football to focus on her paramedic career.[4]