There’s another post on this exact sub discrediting this as an idea. If someone’s acting inappropriately, that’s that. Their relationship with you is absolutely no excuse for them to act that way, and being related to someone does not mean we’re obliged to take abuse from them.

Not sure of your living situation but once a person gets some regular distance from their family, it’s easier to view them for who they are as people (for better or worse!).