NSW woman kidnapped, 'thrown off' bridge

A Sydney woman has survived being thrown off the Windsor Bridge into the Hawkesbury River in an alleged kidnapping and botched murder attempt.

The Campbelltown woman, 19, has told police she was driven in the boot of a car to the seven-metre-high bridge before a group of people threw into the river below in the early hours of Sunday, police say.

Surviving the fall, she swam to the riverbank and alerted police.

Police on Wednesday alleged the victim had been kidnapped on Saturday night in Campbelltown before being driven to Windsor, 60 kilometres away.

A girl, 17 and a woman, 19, presented themselves to local police and have since been refused bail on charges of attempted murder, aggravated kidnapping and other offences.

The girl is due to face a children's court on Thursday while the woman is expected to face Penrith Local Court on November 23.

Police are still inquiring whether two men were involved in the incident.

A Holden Commodore found a home in Whalan has been seized.