I feel so bad for the archduke, he probably did that because:
1) He didn't want to disturb her
2) She didn't know what would happen if she really had died.
Like, she is alive, but her original intention was to die, so this all would be happening and she would be gone from it.
Charlotte, babe..... I don't know what I want, her to reconnect with her disciples or find love (in archduke), we will see...