What is the method for treating my sister and eliminating the "Tabi'ah" (a female demon or jinn said to accompany a person and cause misfortune) that prevents pregnancy, especially since she saw in her dream snakes, cats, and jinn sleeping between her and her husband?

There is no definitive cause for infertility, but magic is real, and protection from it comes through divine safeguards and legitimate ruqyah (definition) (exorcism). It is advisable to supplicate with the prayers of the prophets, such as the supplication of Zachariah (peace be upon him): "My Lord, grant me from Yourself a good offspring. Indeed, You are the Hearer of supplication," and "My Lord, do not leave me alone [with no heir], while You are the best of inheritors." And the supplication of Abraham (peace be upon him): "My Lord, grant me [a child] from the righteous." It is also advisable to supplicate with the prayer of Jonah (peace be upon him): "There is no deity except You; exalted are You. Indeed, I have been of the wrongdoers," and to frequently seek forgiveness, for Allah (the Most High) says: "And said, 'Ask forgiveness of your Lord. Indeed, He is ever Forgiving. He will send [rain from] the sky upon you in [abundance]. And give you increase in wealth and children.'"