The woman charged over a horror head-on collision that left a mother and son dead has been accused of offering no sympathy to their grieving family.

Athena Vibert, 50, has been charged with dangerous driving resulting in the death of Julie Bullock and her seven-year-old son. Mrs Vibert was not present at Picton Local Court on Tuesday, and was represented by her lawyer Tony Venditti.

Darren Bullock outside court on Tuesday. Credit:Ashleigh Tullis

Mrs Bullock, 49, and her son were killed when their Mazda four-wheel-drive collided head-on with Mrs Vibert's Holden Astra, after she allegedly crossed the median strip on the Hume Highway near Pheasants Nest on March 7.

Mrs Bullock was driving her twins to school about 8am when the crash occurred.