Are the symptoms experienced by the mother—such as distress, crying, tingling, yawning, inability to pray and read the Quran, and the presence of incense smell in the house—related to envy (hasad) or jinn possession (mass), and should the house be vacated?

If your mother finds harm in the house and wishes to move, there is no sin upon her. It cannot be definitively asserted that what afflicts her is envy (hasad (definition)), but we advise her to perform ruqyah (definition) (Islamic exorcism/healing) upon herself using prophetic supplications and invocations, to frequently recite Surat Al-Baqarah in the house to expel Satan, to recite Qur'an over water and bathe with it, and to consistently perform acts of worship and prescribed remembrances like morning and evening adhkar. She should also seek Allah's help and make abundant supplications to ward off evil.