The Duchess of Cambridge
might have U.S. Vogue knocking on her door
, but it seems the newlywed is just as happy in Topshop as she is in couture.
On Monday evening, Kate was spotted at her local Topshop branch on Kensington High Street, making some quick purchases just before the store closed. Thrown over her arm as she waited patiently in line was a smart polka-dot skirt
in teal (available in the U.K. only), a cobalt-blue boucle jacket
with velvet trim and a delicate pair of gold-effect leaf earrings that cost just $10 and change.
In casual black jeans and a tweed jacket, Kate browsed the store for a half-hour before joining the line to pay for her $170 worth of items.
"She was low-key and casual – she seemed so normal," the Topshop staffer who served her tells PEOPLE, adding: "She was really chilled out despite some customers in the queue behind her saying, 'Oh my God it's her' and pointing – she didn't seem fazed by it all and she was really sweet."
Despite the commotion, no one approached the famous shopper, who gave the store no prior warning that she would be coming in. "I haven't seen her before so I don't think she's a regular but she lives at Kensington Palace, just 'round the corner from here so it makes sense," the staffer added.
The Duchess will officially step out again on Thursday, when she and husband Prince William
open a children's cancer center
at the Royal Marsden Hospital.