My daughter just lost her first tooth and I’m wondering if you have any thoughts on telling kids about the Tooth Fairy and whether it’s harmless or if it borders of issues of chukat HaGoyim or Geneivat Da’at.
Interesting… I don’t think it is chukat HaGoyim, unless you think that we have to stop reading stories of Peter Pan and Pinocchio, etc. I guess this is somewhat worse because you are telling her that it is a real thing. I am having a hard time framing this issue halakhically, but I would say that I would feel a lot more comfortable if you said that a “malakh” comes and leaves money behind. That would definitely make it much more Jewish, and at some level isn’t even sheker, as humans are also messengers (and even messengers of God).
Geneivat Da’at is only when you tell something to someone so that they are beholden to you, even if you were never intending to do something for them. It is not about lying per se. Inviting you to my wedding when I know you can’t attend is Geneivat Da’at.
What it is is sheker. But – that is not absolutely forbidden. The Gemara allows white lies and the like (מותר לשנות). Why exactly that would be justified here is not clear to me – maybe you think that there is something beneficial from a parenting perspective in telling her this? If you are only doing it because it is part of American culture, and that there is no real “good” reason to do it, then I would not do it.