She spies on them.

With her new powers, it's easy to hide herself from their simple human sight, and wait for them to come in.

"Hello? Sarah?" Holly called out, and waited for a response. "That's weird, she said she'd be waiting for us."

"Maybe she decided to give us some privacy?" Nick suggestion.

"It could be, but I figure she'd tell me about that beforehand, right?"

"Maybe. It's too bad though, I was looking forward to spending some time with her." Sarah's heart beat a little faster, imagining that he had secret feelings for her.

"Yeah, me too. She might just have gone out or something."

"Or maybe she's exploring the house. It looks pretty big."