The 26-year-old, who was capped three times by the Black Ferns, made the announcement on social media.
"Scans have come back showing a brain injury that means I need to hang the boots up, medically retire and never play rugby again," she said.
"Grateful that my health is still intact and we found out before it was too late."
A niece of former All-Black Paul Steinmetz, she made her Black Ferns debut against Australia in 2022 on the back of an impressive Super Rugby Aupiki season with Matatu.
Head injuries are a serious issue for rugby union, with a class-action lawsuit brought by a group of former British players underway.
They allege that World Rugby, the Welsh Rugby Union and the Rugby Football Union failed to establish reasonable measures to protect their health and safety.
