How does weak and sickly Lady Madeline escape from the copper and stone tomb in "The Fall of the House of Usher"?

Madeline's robes were bloody, and the tomb was not a permanent place of rest, but you're assumption that Madeline never lived to begin with just might be correct. Every description of Madeline prior to her escape from the tomb alludes to a ghostlike being. She doesn't speak, nor does she acknowledge..... she moves as if an apparition. It isn't until Roderick and the narrator entomb her that she is describe with the attributes of a living being.... "the mockery of a faint blush upon the bosom and the face, and that suspiciously lingering smile upon the lip which is so terrible in death."

We also know that Madeline's reappearance is supernatural..... only Usher knows she stands outside the doors, and no one opens the doors..... they open of their own accord. When the men saw Madeline, "There was blood upon her white robes, and the evidence of some bitter struggle upon every portion of her emaciated frame." Thus, she freed herself from the tomb, but that doesn't mean she was real..... or should I say a breathing, human life.