Mig describes her mother as cheerful and brave, although Mig is often deprecating about these very qualities. Both children find their mother's determined optimism irritating, and notice that Betty is too easily manipulated by guilt and embarrassment -- too quick to take on responsibilities to other people. "Really it is difficult having a martyred crusading saint for a mother sometimes," Mig writes in exasperation. Betty is deeply and instinctively compassionate -- she immediately adopts the stray cat, and springs into action to help Antony Green, seeing his suffering where Chris and even Mig saw only a mystery. Perhaps it is this capacity which makes her an easy target for emotional blackmail.
But Betty, who never uses guilt to motivate other people, realizes and resists when guilt is systematically used to control her and her children. There are signs, early in the book, that people tend to underestimate Betty's strength; when the book starts, Betty had recently demanded a divorce from her husband Greg, and both her husband and children are astonished. "I can't get over it being Mum who [ended the marriage]!" writes Mig: "Nor could Dad, I think."
As a mother, she is loving and humorous even under great strain, and fiercely protective of her children when threats arise. Mig tells us that "Mum never lies," which is enough to set Betty apart from most DWJ parents. Throughout the book we see that she is keenly aware of her children's personalities and moods, and is willing to learn from their insights.