My daughter& #39;s bedroom door opens OUT and doesn& #39;t have a lock on the inside. We& #39;re trying to think of ways we can lock it because her dad just barges in after a knock. The door frame is too thick for a latch...any ideas?

Dad is in no way, shape, or form going to change. My daughter is trans and he doesn& #39;t recognize that. There are definitely deeper issues here but for the time-being I& #39;m just looking for a way so that my daughter feels secure in her space.