Tree dwellers feuding with Stone dwellers?

Trying to find a book that seemingly just ceased to exist. It's about a young girl/teen, who becomes an orphan and has to move in with her aunt or grandma. This relative she loves in with lives in the base of a tree, and once she moves there she begins to learn more about her mothers and fathers families. Her mother was from a group of "tree dwelling" people, and her father was from a "stone dwelling" family. Unfortunately, these two families or clans were feuding, and her parents love was forbidden. She's thrown into a mix of trying not to be kidnapped by her fathers side of the family, and she has to figure out how to get them to stop feuding. I know the cover had a redhead girl running down stairs carrying a torch, and I believe the author was a female. I've been trying to find this book for years, help 😭. It did exist back around 2010-2012, and it was in a library.