Who is Steven Regan from Pictures of Hollis Woods and what is their importance?

Steven Regan is the brother of the Regan family, the family who wants to adopt Hollis Wood. Steven meets Hollis at the diner with the Old Man, and when they play checkers, she lets him win. Steven teaches Hollis how to fish and drive, and he also takes her halfway up Old Man's Mountain, sharing his candy bar with her and giving her the bigger half. He is very happy when his parents plan to adopt her.