Who is Margaret Dillon from Lily's Crossing and what is their importance?

Margaret Dillon is Lily Mollahan's best friend in Rockaway. Margaret is ten years old, the same age as Lily. Margaret lives with her parents and older brother Eddie, in the Jamaica section of Queens in New York City. Margaret Dillon has a serious sweet tooth and a heart of gold. This is evident when Margaret gives Lily a half-eaten Milky Way bar for her birthday. In her defense, though, Margaret does share a huge stash of candy with Lily, much to Lily's pleasure.