Tooth Fairy concerns

My darling older daughters made me laugh tonight! Courtney lost one of her molars while brushing her teeth. She has lost most of her teeth by this point, but she always gets excited about it. I mean, what kid doesn't get excited about an extra $1 for doing nothing except growning up? At one point she asked me if I would tell her who the tooth fairy was. Jessica asked if the tooth fairy was tiny or if she was big like me. I said I would leave that up to their imagination. Courtney again asked me when I would tell her who the tooth fairy is. She told me that if it was the parents who do it, then she should know for when she is a parent. She'll have to know to do it. The funniest thing came next. She asked me if I would tell her who the tooth fairy was when she turns 18. Of course, I promised that when she's 18, I will tell her who the tooth fairy is! (Jess wanted to be told at the same time as Courtney, but she will be 16.) She then thought that I promised that because my hope was that they would forget before then and I would not really have to tell them. I said "I will be happy to tell you who the tooth fairy is when you are 18!" I thought it was funny and had to share!