i think she'd side with izaac a lot on things because sometimes her loyalty can be blind, so during the more volatile downs in their relationship marsy likely said things or had words with her even if they weren't fair? depending on the details. for the most part if they became friends after she moved to nyc and in with izaac for awhile she'd honor that. she doesn't think fights or having annoyances with people should result in them not being friends.