K.L.
Im not a big fan of chain stuff, but I can see how cute/fun it can be with stickers for a young girl . I think if shes friends with one child, but happens to play with the siblings you can do either If you do send to all the brothers and sisters then their M. will have to try and find enough kids to send letters to from each of her kids,,making it tougher on her. Id send to just the friend and let it be her special thing, and not always having to share with her siblings. It just seems like theyd like to get something all their own now and then. Have fun with it.