Britain's Catherine, Duchess of Cambridge, holds her baby daughter, Charlotte Elizabeth Diana, outside the Lindo Wing of St Mary's Hospital, in London, Britain May 2, 2015. The Duchess of Cambridge, the wife of Prince William, gave birth to a girl on Saturday, the couple's second child and a sister to one-year-old Prince George. REUTERS/Suzanne Plunkett

The “Kate Effect” strikes again! This time around it’s the baby clothes that Princess Charlotte wore for first pictorial that’s becoming a hot item for mommies.

Since the release of Princess Charlotte’s first royal portrait alongside big brother Prince George, public interest for the clothes that the royal baby wore has risen, reported People on Wednesday. William and Kate’s youngest child was wearing baby clothes from Irulea, a Spanish children's wear and home goods boutique. Ayago Villar, co-owner of Irulea, told People exclusively: “We're overwhelmed! The store is full of people and they want any item related to Princess Charlotte.”

It seems Princess Charlotte already wore something from Irulea when she was first introduced to the world on May 2. The wool bonnet that was atop her head then was also from the Spanish boutique. The royal baby’s outfit during her first pictorial was head-to-toe Irulea, too – from the hand-knitted white wool sweater, the white cotton top with frill collar, up to the white wool pants or polaina, as Villar calls them, where all from Irulea. "Right now I'm getting a lot of demand for the little polaina, as well as the little handmade shirt that she was wearing under her sweater," reveals Villar.

Villar also revealed that Irulea experienced a surge in sales and how there’s a huge interest for products that they make by hand, especially for their newborn range. Villar told Hello! on Monday, "We've had orders from abroad – we're seeing a massive repercussion on an international scale. A lot of people have asked for copies of Princess Charlotte's clothes so we're making more. Everyone's delighted really."

There is no question that Kate’s influence on small business has been known to literally see tiny labels launched into fully fledged companies overnight. An article at Marie Claire published last month recounts how a similar thing happened with fashion label Beulah. Natasha Rufus Isaacs, co-founder of ethical fashion label, told the magazine: “We were a relatively unknown and young label, and it definitely helped spread the word about us and the cause that we support.”

The “Kate Effect” is truly a powerful phenomenon. She’s not the only "fashionista" in the family; it seems her children, George and Charlotte, are, too.