Will the Real Tooth Fairy Please Stand Up?

Lindsay recently reported that Claire and Margot were puzzling over the "real" identity of the Tooth Fairy.   Their discussion was prompted by Claire's (truthful) claim that I had come into her room and "rustled around" on the same night she'd left a tooth under her pillow.  When I overheard them discussing the topic, I decided to be straight about it (while crossing my fingers that they wouldn't disclose their new-found info to Jane, who is still very new to the whole Tooth Fairy business).

Me:  "Okay, you guys -  I have to tell you something.  But you cannot tell Jane."
Margot:  "We won't tell her, we really won't!  Is it about the Tooth Fairy?"
Me:  "Yes.  And it's very important that you not let Jane know what I'm about to tell you.  Okay?"
Claire:  "Mom - can you just tell us?!"
Me:  "Well, Claire, I know that you told Margot you saw me come into your room the other night when you'd left your tooth out for the Tooth Fairy.  And you're right - I am the one who has been taking your teeth."
Margot:  "I knew it was you!  I knew it!"
Claire:  "Okay, fine.  So, do you just mail them to the Tooth Fairy, or what?"