Ms Longhurst, 31, an English and music teacher at the 96-pupil school, had been missing since March 14. Last Saturday, her remains were discovered on Wiggonholt Common, in West Sussex.
A post-mortem examination revealed that she had been strangled several weeks before. The murderer attempted to dispose of her body by setting fire to it.
Paul Atkins, head of Uplands, has asked parents to keep their children at home on Monday, after the Easter holidays, so that staff can discuss how best to grieve. He said: "We need some buffer time for staff to talk among themselves. They will be tremendously upset."
Ms Longhurst was a popular and dedicated teacher, he said. Since her arrival at the school in 2000, she had revitalised the music curriculum, running after-school clubs in drumming, keyboards and dance music.
Educational psychologists have been at the school to offer staff and pupils support since Ms Longhurst's disappearance. And Mr Atkins will conduct an all-school assembly on Tuesday to help his pupils deal with the bereavement.
Eventually, he hopes to hold a commemorative service for Ms Longhurst. He also intends to establish a permanent memorial, developed in consultation with his staff. Among his proposals is a music trophy for pupils in Ms Longhurst's name.