People have already given you good advice, but I would add a couple more things. First, Christmas is a very, VERY bad time to introduce a puppy to the home. Excitement is running high, people are distracted and there are WAY too many dangerous things for the puppy to get into. Puppies need a calm, stable, predictable environment to help them get used to their new home. If at all possible, ask the breeder if you can leave the pup there for one more week. Put a cute stuffed animal and some puppy supplies with a promissory note for the real thing under the tree. Your daughter will still be thrilled beyond reason, she will have the fun of helping you set things up properly for the puppy. You can spend the week help your daughter understand the needs of a brand new puppy, and what to expect. Then you can bring the puppy home into a calm, quiet situation where he or she is the center of attention for the first few days.
Remember, a puppy is a very small baby, and coming to a new home, even WITHOUT the Christmas overload is pretty overwhelming. Set things up for the best chance of success for you, your daughter AND the puppy. Puppies are not toys, and IMO, should not belong to a single person as a "gift". You are bringing a new family member into the household, and that new and vulnerable family member's best interests have to be taken into consideration too!
Finally, another thing that other people haven't mentioned is to get the puppy signed up for puppy kindergarten as soon as possible. Early socialization is TERRIBLY important for any dog, but ESPECIALLY for a dog meant to spend time with children. Puppy K is THE best way to give the pup lots of socialization in a safe, controlled environment. At the same time, you and your daughter will be learning to handle the problems that inevitably come up with a new puppy.
Oh! And have a wonderful time on your new adventure. With some proper planning and guidance, you and your daughter will enjoy your new dog's puppyhood without finding it an overwhelming challenge.