All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
I advise this woman to:
1- Ask Allaah the Almighty for protection when she sees such things.
2- Say the night and day Athkaar (mentionings of Allaah) regularly.
3- Mention the name of Allaah the Almighty frequently.
4- Read the Quran frequently.
5- Remain steadfast in doing good acts.
6- Abstain from doing bad acts.
This, Allaah willing, will help her to overcome such hallucinations. Devils, in most cases, can be the cause of such things. She may also want to see a psychologist.
Allaah Knows best.