A woman has been remanded in custody after being charged with attempting to murder her seven-year-old son by twice ramming her car into him on the far south coast of New South Wales.

Police allege the 39-year-old woman hit the child with her car twice while he was walking in Corrigans Beach Reserve at Batehaven, just south of Batemans Bay, about 3:00pm on Monday.

Witnesses said they heard a car mount a kerb and thought it was somebody doing circle work before the incident.

Another witness was driving by when she saw a child being circled by a car in the park.

"The boy was moving while looking at her, going around and around and around in circles, as well," Lavina White said

The boy was taken to Batemans Bay Hospital with a fractured collarbone after witnesses at the reserve helped him, police said.

The woman, who cannot be named for legal reasons, was arrested at the scene and later charged with attempted murder, assault occasioning actual bodily harm and driving a motor vehicle furiously and causing bodily harm.

She appeared at Bega Local Court today where she was remanded in custody and a mental health assessment was recommended.

The court heard the woman's other child, aged four, was present during the incident.

Both children are now in state care and soon will be taken to other family.

The woman will remain behind bars until she is expected to face court again next month.