Q: Unmerging Music Library

My sister recently purchased the apple music family plan in order to share it with me. In creating a family and trying to get apple music on my iPhone, nothing would work. Finally, I decided to sign out of my apple ID in the iTunes tab in settings and sign in with my sister's apple ID. This resulted in our music libraries merging, but did give my access to apple music. Me and my sister didn't like the merged libraries so I signed out of her apple ID on my phone and signed in with my apple ID on my phone and my library returned to normal, but her library is still merged. I've tried signing out of iTunes and iCloud which removes my music but also removes all of her playlists and all of her apple music. When she signs back into iCloud, there is no change, but when she signs back into iTunes, the merged library returns. Does anyone know why this is happening and how to return her library to how it was? Or at least undmerge the libraries. Thanks!