Samir Hussein, WireImage

Queen-to-be Kate Middleton
stepped out for her Nov. 16 engagement announcement in a figure-flattering electric-blue jersey dress that immediately had royal watchers and StyleList readers asking, "Who made it?"

The answer may be the first hint of Middleton's lady-in-waiting for the role of royal wedding dressmaker: London-based designer Daniella Issa Helayel.

The Brazilian-born Helayel -- whose label Issa is tops among A-listers in London and beyond -- is already an established favorite of Middleton, who will marry Britain's Prince William sometime next year.

"We are thrilled with the engagement news, and I'm very happy that she has chosen to wear Issa today," the designer told People.

Middleton wore a stunning bright-blue custom Issa dress to friend Harry Meade's wedding last month and a black frock by the designer to the May wedding of royal cousin Peter Phillips to Autumn Kelly.

And as royal luck would have it, the Daily Mail recently reported that Helayel is now making wedding dresses.

Helayel's celeb clientele has included Jennifer Lopez, supermodel Naomi Campbell, and Madonna as well as GQ's "Babe of the Year" Scarlett Johansson. She is also a favorite of princesses Beatrice and Eugenie, the daughters of Prince Andrew and Sarah Ferguson.

Helayel, who once studied law, opened her design house in 2001. She told British Vogue in 2008 her philosophy is "that our clothes can be worn from the beach to the office and then the red carpet. They are the ultimate in a dress-up, dress-down approach, to be slipped on to work with effortless elegance any time of day."

As for her high-profile royal client: "It makes me very happy she wears our clothes. She's a beautiful girl," Helayel has said.

Certainly, Middleton has options if she follows protocol and sticks with a native Brit for her high-profile walk down the aisle. Vivienne Westwood, John Galliano, and, of course, Stella McCartney, the daughter of rock royalty, could easily play the role of designer of honor.

McCartney made Madonna's dress for her 2000 nuptials to director Guy Ritchie. It was Westwood, of course, who outfitted Sarah Jessica Parker in a big way for Carrie's ill-fated wedding in the original "Sex and the City" film.

Love Kate Middleton's fashion sense? Check out this roundup of her best style moments.

For more royal wedding dish, read about Middleton's storied sapphire and diamond engagement ring.

And for our wedding watch closer to home, read about Jessica Simpson's unusual sparkler.