"I always shock them," DiFerdinando said with a laugh. "For me to approach them so casually, it always makes their day."
Besides building good will for her brand, DiFerdinando uses the interactions to talk to salespeople to gain insight. "They see all the trends," she said.
DiFerdinando's success comes as no surprise to local retailers who carried her brand early in her career.
"I thought she was very talented," said Sima Blue, owner of Trillium, a boutique in Green Spring Station that carried DiFerdinando's bags around the same time as Bergdorf Goodman. "She just presented herself very well. ... But it's not just the talent — it's the motivation behind it."
George Sakellaris, owner of Handbags in the City in Harbor East, also has fond memories of the burgeoning designer.
"She's great," he said. "She was so much fun to work with."
Sakellaris sees a lot of potential in DiFerdinando.
"She has some very fun designs," he said. "They are different from a lot that is out there. It's great for the city. ... She's pretty big. She's only going to grow."
DiFerdinando attributes much of her work ethic to her father, David DiFerdinando, founder and owner of Boardwalk Fries, a chain with locations in 40 states.
She recalls working at his eateries starting at age 6. "I had to stand on a soda box to reach the counter," she said. "My parents taught me if you wanted something, you had to work for it."
Her father remembers his fashion-curious daughter first experimenting with designing ties at 12, and then transitioning into making purses at 16 after reading about how much more profitable the handbag industry was.
"She's very ambitious and very talented," he said. "She's putting out a product that other women like. It's amazing. I hope that she will become the next Kate Spade."
That might not be too far from reality for his daughter, who already has eyes on expanding her brand. This year, she launched a line of soft goods such as wallets and iPad cases. And there's more to come.
"I want to create a lifestyle brand," she said. "I want to design shoes, home goods and go into clothing. I just want to expand."
But DiFerdinando appreciates what she's achieved. "I'm so grateful to be in this position," she said. "I'm living the dream."