In Mark Haddon’s novel "The Curious Incident of the Dog in the Night-Time," Christopher's mother, Judy, believes that leaving would be better for the family. This conclusion stems from the intense strain that Christopher's behavioral challenges and his father's struggles to cope with them place on the family dynamic.
From the perspective of the characters, Judy's departure can be seen as both a relief and a hardship. On one hand, her absence allows Christopher's father, Ed, to take on a primary caregiving role, which could potentially foster a stronger bond between them as they navigate their challenges together. Judy's decision could also be interpreted as an act of self-preservation, as she finds it difficult to manage the pressures of being a mother to a child with autism, leading her to believe that her leaving might ultimately create a more stable environment for Christopher.
However, on the other hand, her decision also results in emotional turmoil for Christopher. He feels betrayed by his mother’s departure, grappling with feelings of abandonment and confusion. This greatly impacts his ability to trust his father and others, exemplifying how Judy's choice might not have been the best for Christopher's emotional well-being.
Ultimately, whether or not she was correct can depend on one's perspective; it highlights the complex nature of family dynamics and the personal struggles of each member. The story illustrates that what might seem like a rational decision to an adult may have severe emotional repercussions for a child.