Who is Markie from Willow and what is their importance?

Markie is Willow's best friend. They've been best friends since they were little girls, but after her parents' deaths, Willow found herself unable to speak with Markie because she felt they no longer had anything in common. Markie continued to reach out to Willow despite the fact that Willow never answered or returned her calls. At the end of the novel, they are reunited, and Markie is able to tell Willow how deeply her rejection hurt her.