Stacey Klimovitch, 61, was shot when she answered her front door on June 10, at a home on Queen Street in the Newcastle suburb of Stockton.
Her 31-year-old daughter and eight-week-old granddaughter were home at the time of the shooting.
The pair had recently moved in after becoming estranged from the child’s father.
Police today released an image of a similar looking vehicle that is believed to have been driven following the shooting.
Detectives believe the vehicle to be a dark coloured 2013 to 2017 Holden Commodore VF SSV V8 sedan.
Police say the alleged shooter, a younger man, is known to the family but so far, no arrests have been made.
Anyone with CCTV or dashcam footage is urged to police or call Crime Stoppers on 1800 333 000.