She gasps a little bit and foolishly looks around to make sure no one heard her, forgetting for a second that she's a ghost and only Ms. Sommerset can see her. "That would be wonderful! I didn't think of that possibility at all."

... Clara realises that should have. Seeing how it was Ms. Sommerset who, in a way, guided the conversation to this but she doesn't. Clara genuinely believes this is a luck of the draw for the both of them. "I promise you I can keep quiet and tell no tales to anyone, dead or otherwise."