Here's How Birthday Girl Kate Middleton Keeps Winning at Pregnancy Style—Watch Now

Séraphine designer Cecile Reinaud shares some of the royal's secrets with E! News

By Natalie Finn, Lindsey Caldwell Jan 10, 2015 1:33 AMTags
Prince William, Duke of Cambridge, Catherine, Duchess of Cambridge, Kate MiddletonSamir Hussein/Pool/WireImage

If you don't think that Kate Middleton is one of the most impossibly chic women you've ever seen, then you really just haven't seen a lot of women. And if you haven't appreciated her pregnancy style...we give up.

But presumably you're a fan, and we've got scoop straight from one of the royal's secret weapons—Séraphine founder Cecile Reinaud.

The Duchess of Cambridge seemingly spent her whole first pregnancy sporting some sort of creation from the luxurious and celeb-favorite yet still-affordable maternity brand, which recently opened its first store in New York. And her second go-round has been no different so far, with Kate stepping out in a variety of Séraphine pieces, including—perhaps most memorably so far—a fitted black turtleneck dress when she and Prince William were in New York last month.

Watch: Meet Kate Middleton's Maternity Fashion Designer

So what's it like having one of the most famous women in the world as the unofficial face of the line?

"She just orders like a regular customer, we have an online service, we deliver it at her home," Reinaud tells E! News. "It happens to be a palace but otherwise it's just like any other regular customer."

But while certain items, like the insta-classic black dress (which retails for only $99) and the floral-print nursing frock Kate favored in the weeks after Prince George's birth, are technically available to the masses (should a person be able to snatch one up in the duchess' wake before they sell out), baby bump No. 2 will be cloaked in more custom pieces.

TRH The Duke and Duchess of Cambridge

"We decided to do some special pieces for her, a bespoke line which is something we offer for our VIP clients, as we dress a lot of Hollywood celebrities," Reinaud explains, "so she wore one of our bespoke pieces when she arrived in new York, which is a coat, and she's got quite a number of bespoke pieces that we've made for her."

And Kate did dazzle in a very Chanel-reminiscent burgundy Sèraphine coat when she and William touched down in the Big Apple.

Making more custom pieces is "very appropriate, Reinaud added, "because she has a lot of functions where she needs something extremely elegent and formal, which is not necessarily what people would wear on a daily basis, so it's not part of our range. And we love the idea of giving her some unique piece that still reflects the brand."

They really couldn't have hoped for a better model. Kate's fellow Séraphine fans include ShakiraZoe SaldanaGwen StefaniAli Larter and Alicia Keys.

Watch the full clip above to hear more about Kate's very "distinct tastes," as well as Reinaud's birthday (and fashion) wishes for the royal, who turned 33 today!

Can't get enough royal news? E!'s new scripted series The Royals premieres Sunday, March 15, at 10 p.m.! Follow The Royalson Twitter and Facebook for the latest updates!