Helen Grady (Madness)

This is a question page in regards to the reasons behind Helen Grady's madness.

Question
Helen Grady is the mother of Travis Grady and the wife of Richard Grady. When Travis was a young boy she attempted to kill him as the "people in the mirrors" convinced her that he was a "Devil" and told her to carry out this task, after the failed attempt on her sons life she was institutionalized at Cedar Grove Sanitarium, where doctors noted that she harbored strong fantasies and a violent persecution complex. Often when her husband would come to visit she would become violent against him and demanded to see her son almost like she had a "goal" that she needed to accomplish.

"Notes: Patient continues to harbor strong fantasies and a violent persecution complex. Her moods can swing from calm to violent aggression in a short time, which has led to her being moved to the seclusion wing. She becomes particularly violent during the occasional visits from her husband, demanding that she be allowed to see their child. - Medical Report found in Cedar Grove Sanitarium"

The main question is why? The root cause seems to be the "people in the mirrors" However this seems very delusional much like her statement that she could leave the sanitarium any time by using those same mirrors. If so then why didn't she? Why didn't she use the mirrors, escape and complete her goal of killing her son? It seems she just went completely mad. The question is why did she all of a sudden lose it and start talking about people in the mirrors? Richard Grady seems to point to the idea that at one point Helen Grady seemed to be completely normal and lead a happy life, one which he so longed for after what he saw his wife had become. Did something happen almost at that specific point in her life which made her go mad then? Perhaps she had some repressed memories of her own childhood, that were only triggered when Travis reached a certain age? Perhaps all this nonsense about mirrors is based on the theory that Travis had become a mirror image of her past, meaning perhaps he was already going through some issues before the abuse? Something definitely sparked this madness the question is what?