We found 3 Reddit comments about Aurora World 10" Dolphin Puppet. Here are the top ones, ranked by their Reddit score.
Searching amazon I found blonde 50s wigs with a bouffant or beehive will kind of give you the shape you need in her hair
And then this
And with those two things, and a trip to Walmart to find some beige skirt and peach or pink top you have
It's not quite the exact replica of Pam's puppet but this one is reasonably priced and pretty damn close: http://www.amazon.com/Aurora-World-10-Dolphin-Puppet/dp/B006UPI07E
Or you could just buy it on Amazon