And while Holly hates 90 percent of her outfits when she's inside Williamson's apartment, the second her toes touch the pavement outside, she's a new woman. "I swear she poses! If anyone within a 100-foot radius has a video camera, she will run up, tail wagging, ready for her close up," she tell us.
The pair is inseparable and that is exactly how Williamson wants it.
"We are best friends, thick as thieves, two peas in a pod - you name the cliché and it fits us to a T," Williamson tell us. "In about three years, Holly's been on more than 60 plane rides, visited at least four states, and worn more than 50 outfits. We get to experience all of these adventures together, and I can't think of a more fun companion to have by my side."
This kind of attention combined with Holly's many experiences has Williamson dreaming of writing a book. "I would love one day to write a series of Eloise-esque children's books telling the story of Holly's adventures (and ensembles) in Manhattan - donating proceeds to charities close to our hearts."