The crash happened about 3.10pm on Saturday.
She was initially taken to the Dargaville Medical Centre and then flown to the Whangārei Hospital.
A second person, believed to be a male, was attended to by St John paramedics at the scene.
In another crash, emergency services were called to state highway 1 just south of Kawakawa about 12.50pm yesterday after a car went into a ditch.
The driver suffered moderate injuries.
Temporary road closure
A temporary road closure will be in place along Tutukaka Block Rd between 10.30am and 11.30am this Wednesday, August 4.
There will be no access to and from that road during the closure and motorists are being urged to plan ahead.
The closure is to allow for pole replacement to be carried out by Northpower.
Stop/go traffic control will be in place outside of the closure times, from 8.30am to 4pm on the day.
Smile free dental day
Smile NZ free dental day programme is offering one treatment for Community Service Card holders for free in Northland, starting next week.
The free dental days will be held at Gentle Dental in Ruakākā on August 13, Mangawhai Dental Clinic on August 14 and 21, and at Kensington Dental Centre in Whangārei on August 21.
People are advised not to call the dental practices directly but to call 0800373376 to book an appointment.
Help at community lunch
The Otamatea Kaipara Community Services is on the hunt for two to three volunteers to help out once a month with its community lunch.
The lunch is held at the Mangawhai Community Hall.
Those keen should contact Pauline Wilson on 0212510225.
The next two events are at the St John Hall at Maungaturoto on August 4 and at the Mangawhai Community Hall on August 12.
Play accordion
A free trial for those keen to play accordion will be held at Oromahoe, starting at 3.45pm on Tuesday.
Children between the ages of 5 and 8 will learn to read music, play individually and in a group.
Parents are welcome to learn alongside their children.
Contact Debbie 02108211637.