In human form, she is a small girl with long white hair reaching her ankles.
In bird form, she is notably fatter than the small birds she turns into; likely a limit to compressing her body mass. Any minute weight she may have gained also translates to her avian forms, as Lily noted Maggie had gotten a little fatter as a bird (due to eating well with the Witch Union for a while).
Despite being an adult, Maggie often behaves childishly like Lightning, seeing missions as child's play. The reason why is unknown, but it's possible she awoke as a witch in early childhood, thus never having a chance to properly grow up mentally. She also shows traits commonly seen in the birds she transforms into.
She used to live in the slums of King's City like a real bird, in order to prevent herself from being caught by the church. By squeezing herself into the narrow beams of the roof to pass each night, some time later Ashes and Tilly found and accepted her. Every sound she heard woke her up immediately, meaning she had never slept properly before meeting Tilly.
Maggie was sent to check up on Ashes, who had gone to the Western Region of the Kingdom of Graycastle.
- Among witches from Witch Union, she was the fourth to evolve her ability.
- Maggie is unique among the transforming witches, as when she transforms, her clothing disappears and re-appears as needed; Lorgar and Joan have to discard their clothing to transform properly.
- Upon meeting Lightning for the first time, they became explorers together and provide food for the witch union everyday by capturing prey. The relationship is unique, because only the two of them can fly fast using their magic.
- Roland does not know how Maggie's transformations ignore the Law of Constant Mass; especially with her demonic bird transformation.
- She has extraordinary luck. There are several examples, including how she gets most of the multiple choice questions on tests correct despite not knowing the actual answer, when her test score got "increased" from 17 to 117 by a gust of wind, and many other examples.