What is the ruling on a menstruating woman reciting from the Mus'haf out of necessity to calm a woman afflicted by jinn possession?

It is not permissible for someone who is not in a state of ritual purity (wudu'), including a menstruating woman, to touch the Qur'an, due to the Prophet's (peace be upon him) saying: "None shall touch the Qur'an except one who is pure." A menstruating woman may recite the Qur'an without touching the mus'haf, such as reciting from memory, or with an barrier, or from a mus'haf of exegesis (tafsir (definition)). Since the forbidden act has occurred, she must seek forgiveness and repent.