Korrey Whyman - 28, from Kawerau - was shot inside a vehicle as it travelled on State Highway 3 towards Mourea.
She was hit in the head with a bullet and later died in hospital.
A 30-year-old man from Rotoiti is due to appear in the Rotorua District Court today.
He is charged with murder and faces additional firearms charges.
Police said with a large team working on the investigation, further arrests were likely.
"Our investigation will continue until those who are responsible for the death of Whyman are held to account.
"We know that there are several people closely linked to those involved in Whyman's murder, some of whom may have actively assisted these people in some way after the fact."
Anyone helping those responsible avoid police or who witheld information linked to the incident were potentially committing serious offences, police said, urging such people to come forward immediately.
"They should remind themselves that Miss Whyman was an innocent single mother of three young children, all of whom have now lost their mum through the actions of others," Detective Inspector Lindsay Pilbrow said.
Police continue to focus on the movements of a dark blue Toyota Hilux king-cab ute believed to have been used by those involved in Whyman's death.
Police want any information from the public as to the movements of a dark blue Toyota Hilux king-cab, in the State Highway 33 area near Mourea late on the evening of Saturday 24 September or the early hours of Sunday 25 September.
The ute was found burnt out on Braemer Road Reserve on 27 September.
Anyone with information can contact police on 105 and referencing file number 220925/5119, or anonymously via Crime Stoppers on 0800 555 111.