[kjc]

I would get two of all toys.

Then, you need to be able to protect the puppy from any harm. The older dog needs to be watched and corrected, until the pup is older and big enough to take up for himself. You will need to teach the older dog to play gently with his new little sister.

At the same time you can't let the pup get too wild on the older dog, and I would intervene before anyone gets hurt.

Also, lavish attention on the older pup so he does not get jealous.