My dear one,
For your mother, the main thing is to make very strong confession to the guru, by doing the Samayavajra practice and reciting the mantra 1.4 million times. She must do each session with the four remedies, as we do with Vajrasattva. The result she is experiencing now is due to broken samaya with the guru in the past; something happened in the past with the guru.
She should start each session with the Thirty-five Buddhas confession, and recite one lam-rim prayer in each session. Then do the mantra recitation, with the four remedies. This is very important for her to do. It’s not necessary for her to do retreat, but she should do whatever she can each day.
With love and prayer...