On the ferry, same as us. The spirits take it to her. They're all very intent on keeping her happy, isolated, and permanently in that lighthouse from the sound of it.

[So yeah, they guard her, but they also bring her things. It makes for a strangely comfortable prison, but it's clearly a prison nonetheless. Being unable to leave a lighthouse for twenty years would drive anyone insane. It doesn't excuse her, but it does explain a few things.]