Lawyers for a Tauranga woman accused of being involved in the aggravated robbery and kidnapping on the Kaimai Ranges last year are attempting to stop charges proceeding based on her mental health.

Jovaan Graham's body was found dumped outside Pohlen Hospital in Matamata after she was hit by a car on State Highway 29.

Defence lawyer Taryn Bayley filed the application for a stay of proceedings against Cheyanne McCausland in Tauranga District Court this morning.

McCausland, 23, is alleged to have helped Thomas McDonald, 30, to kidnap and assault a driver who had stopped after fatally hitting teenager Jovaan Graham on State Highway 29 on April 2, 2013.

Her appearance was excused from Tauranga District Court today as she is currently getting treatment at the Henry Bennett Centre in Hamilton.

McCausland is charged with kidnapping, aggravated robbery, and two counts of unlawfully taking a motor vehicle.

Police allege McCausland and McDonald were with 18-year-old Jovaan when she was hit and killed on the Lower Kaimai Ranges.

Jovaan's body was then found dumped at the entrance of Pohlen Hospital in Matamata hours after. Read more here.

In court today, Taryn asked for a stay of proceedings hearing for August 4, pending the availability of a psychiatric report. This is to discuss McCausland's mental ability to proceed with a trial in September.