After posting it on Facebook, it’s not a surprise it wasn’t there when she returned.
Also how could the museum have the tooth “ returned” to them if they never had it in the first place.
Good that someone took it home. No different than finding a seashell. And the museum types will fawn over it, catalogue it, and put it in some drawer in a non-public area storeroom, and hide it away forever.
Now someone gets to enjoy it.