Madge is Howl's regular customer, who's name is not mention the film Howl's Moving Castle directed by Hayao Miyazaki of Studio Ghibli.
She lives with her parents in Porthaven. She brought a spell to protect their boat. Markl takes her request, because Howl wasn't at home. She asks Sophie being a witch. Then Sophie approves her guess with a smile.
Madge get self-conscious about it.