Police say that around 7:30pm last night, a woman, aged 24, offered two teenagers, a boy and girl, a lift from Harbour Town Shopping Centre in Helensvale.
She drove them to Mullawa Crescent where the teenagers allegedly produced a knife and demanded her vehicle.
The woman refused and drove away.
In doing so, she allegedly struck the girl with the vehicle, causing serious injuries.
The man fled on foot.
The woman sustained a minor cut to her hand, but refused medical attention.