Natsuko Ito suffered critical head injuries in the head-on motor vehicle accident on the Princes Highway Tomerong on Tuesday afternoon, in which her three-year-old son and four-year-old daughter were also injured.

Police said 30-year-old Ms Ito was travelling south on the highway in a Mitsubishi Magna which collided with a Hyundai sedan being driven north by a 48-year-old Sanctuary Point woman.

The accident happened around 3.20pm about 2.5km south of Hawken Road.

The mother and children were trapped in the vehicle for a period of time.

Ms Ito was airlifted to St George Hospital with critical head injuries but later died.

Both children were taken to Shoalhaven Hospital by ambulance paramedics and later airlifted to the Westmead Children’s Hospital, the son with minor injuries, while the daughter suffered a broken leg which required surgery.

The driver of the other vehicle freed herself from the accident and was taken to Shoalhaven Hospital with minor injuries.

The Princes Highway was closed for several hours while investigations took place, with police saying the accident happened during one of the heavy rain storms which converged on the area on Tuesday afternoon.

Police are appealing for anyone who witnessed the incident to come forward.