* Loss of her father: Meg's father, Dr. Murry, has been missing for years, and she feels deeply his absence. She longs to see him and understands that his disappearance is tied to the forces of evil that threaten the universe.
* Feeling inadequate: Meg struggles with her own self-worth and feels inadequate compared to her brilliant brother Charles Wallace and beautiful twin sister Sandy. She often feels like she doesn't measure up.
* Being different and misunderstood: Meg is an intelligent and strong-willed girl, but she often feels misunderstood and judged by others. She struggles with fitting in and being accepted for who she is.
* Fear of the unknown: Meg is afraid of the unknown and the dangers that lie ahead on her journey to find her father. She fears the unknown forces of evil that threaten to consume the universe and her father.
* The weight of responsibility: Meg carries the weight of her father's disappearance and the fate of the universe on her shoulders. She feels a strong sense of responsibility to find her father and save the world from the evil that threatens to destroy it.
These are just a few of the reasons why Meg Murry is sad. Her sadness is a reflection of her inner struggles, her deep love for her father, and the challenging circumstances she faces.