Mami may resent Camino, but she shows here that she still feels some need to protect her from pain and suffering. This is why she makes it abundantly clear to (presumably) Tía that the funeral must be closed casket. Watching Mami is confusing for Yahaira, as she doesn’t yet realize how complicated relationships can be. It is possible for Mami to have loved (and still love) Papi deeply, while also feeling betrayed by him. But Yahaira immaturely still believes things should be simple and black and white.