Between your child and their teddy bear, it is SERIOUS. No question to fall asleep without it or to forget it at the nunny's.
Yuki teddy bear is a transitional object: thanks to it, your child can be separated from the essential attachment: THE MOTHER. With it, your child can accept and support to not be in permanent presence of the mother. It is reassuring! So this is why you need to buy at least TWO in case one is lost. Avoid the DRAMA. And a hint : DO NOT WASH IT, your child likes the smell. Well, unless it really needs to be washed...