05/16/2016 03:53 EDT | Updated 05/17/2016 02:59 EDT

Kate Middleton Dons Fashion Picks From Banana Republic And Zara This Week

The Duchess, she's just like us!

When you're celebrating the Queen's 90th birthday with the entire Royal Family, you need a rather elegant outfit for the celebrations. And Kate Middleton, the Duchess of Cambridge, did just that for Queen Elizabeth II's birthday gala that took place on Sunday evening.

Sure, Middleton donned a lovely $6,300 white lace Dolce & Gabbana dress for the spectacular two-hour occasion that was held at the grounds of Windsor Castle, but it was her simple red and pleated blazer that had everyone talking. Straight from the racks of Zara, the 34-year-old proved she's just like us mere mortals — a fan of the mall. Coming in at $99, the cape-like blazer featured a Peter Pan collar and two large buttons at the neck. Naturally, the frock is completely sold out on the Spanish retailer's website.

And if Kate's Zara purchase didn't prove how "just like us" she really is, on Monday afternoon, the Duchess sported a $138 Banana Republic midi-skirt to the launch of a mental health charity with husband Prince William and brother-in-law, Prince Harry.

The mother of Prince George and Princess Charlotte paired the skirt with a gorgeous, loose silk blouse from Goat and navy suede pumps. As her for beauty look, the Duchess flaunted her signature blowout and eyeliner.

As noted by Fashionista, this is the first time Middleton has formally worn Banana Republic, which is big news for Gap, Inc. who are taking a tumble in sales. The sold-out skirt is, of course, massive news for the company.

Well, all we have to say is that these two affordable pieces are definitely both a ~knockout~ for Kate.

Follow Huffington Post Canada Style on Pinterest, Facebook and Twitter!

Also on HuffPost

Photo gallery Kate Middleton's 34 Most Stylish Looks See Gallery