The police investigation into the crash remains ongoing.
In a statement on the school's Facebook page, principal Ian Dickinson and Eades announced the death to "our community".
"It is with a heavy heart that we are sharing news with you about our student who was injured on Tuesday," the statement read.
"She passed this morning with family by her side. We are supporting and helping the family where possible.
"Our sympathies and love go out to her family and we will be striving to provide them with any support they need.
"During this difficult time, we are all going to express a range of emotions. We therefore should expect, try to understand, and support a variety of emotions and behaviours.
"We should support discussion about the event, the feelings it gives rise to, and ways of responding."
Dickinson and Eades said they had implemented a plan to respond to the situation to help children and their families.
"Our staff have been briefed on our plans and guidelines both for discussing the incident and understanding reactions. We have been supported by the Ministry of Education specialists in this area.
"Our staff will be available to the children, and we have obtained outside help with supporting the children. As was the case last week, our Library has become a safe space for children to seek advice and share their thoughts and emotions.
"We will maintain a normal routine and structures as the situation allows. We encourage you to do the same. If you feel that your child or family needs assistance or anything else, please contact us and we will do everything we can to help.
"We know that you will join us in our concern, support and sympathy for the family affected by this accident. We greatly appreciate your patience, co-operation and assistance."