POLICE claim a woman was drink driving with her two children (aged seven and eight-years-old) in the car in Rockingham on Saturday night.
About 8.50pm a motorist was travelling on Thomas Road when they saw another vehicle allegedly being driven in a dangerous manner.
The witness followed the vehicle and claimed it was only travelling at about half the speed limit.
It is alleged the vehicle at times drifted to the wrong side of the road and did not have its headlights on.
The witness continued to follow the suspect vehicle while using his hazard lights to warn oncoming motorists.
Police intercepted the vehicle and made inquiries.
A 34-year-old female was charged with no authority to drive (suspended licence) and driving while under the influence of alcohol.
The car was impounded for 28 days. She was bailed to appear in Fremantle Court on June 28.
Police commended the civilian witness for his consideration to fellow residents by warning oncoming motorists and by directing police to the drunk driver.