The woman, who has not been named, was described as "very together" but still angry.
The youth, now 16, admitted at the Old Bailey that he raped the teacher in a frenzied 12-minute attack on September 7 last year. The school did not know that he had been linked to three alleged sex attacks in the six months before the assault.
A spokeswoman for the National Union of Teachers said the teacher was still off work and needed time to recover emotionally. "She is very together, very forceful in her demeanour," she said.
"There is no desire for vengeance, though she is angry that the incident occurred. You don't expect someone to rush into your classroom at ten past four and rape you. She has received counselling and wants to get her life back to normal as soon as possible."
Bernard Regan, the NUT's Westminster representative, who has been working closely with the teacher since the incident, said she planned to return to teaching.
Mr Regan has also provided support for other teachers at the school. "It raises anxieties that this could happen to them. Pupils are also frightened."
He has discussed alarms with senior managers and warned that they should be aware of colleagues working in isolation.