Sounds Like Christmas by Robert Munsch-New

Grandma is baking Christmas cookies, so she asks Lincoln and Georgia to decorate the tree. And what a tree it becomes! In addition to the lights, garlands and balls the kids compete to add some very special and extremely noisy ornaments, including a talking doll, a chirping bird, the neighbour's dog and more. What will their grandparents -- and Santa -- think?

The grandma in this story is Robert Munsch's long-time assistant Sharon and the kids are her grandchildren, Georgia and Lincoln.