Kate Middleton baby
Kate Middleton was spotted at the girls section of children's boutique Amaia in Chelsea.Getty

Kate Middleton has sparked rumours that she is expecting a baby girl.

According to People, the 33-year-old Duchess of Cambridge was spotted at the girls section of children's boutique Amaia in Chelsea.

"She was very interested," co-owner Segolene Tresca said. "Every mum that comes in the shop, they look for boys' [clothes] but they always end up looking at the girls' stuff too. We all hope it's a little girl because it will be so cute, they will be like a little couple."

Kate Middleton and Prince William's second child is due in April.

Previously, there have been several reports about the gender of the royal baby.

Last October, Star magazine claimed that the Duke and Duchess of Cambridge are expecting twin girls.

In December, the same publication claimed that Kate's younger sister Pippa Middleton threw a small, pink-themed baby shower for her.

However, in January, Kate Middleton's decision to wear blue dresses to her royal engagement had some fans speculating she may be having a boy.

Meanwhile, royal biographer Andrew Morton had previously revealed that the royal couple will name their second child Diana, if it's a girl.

"Close friends to William and Kate have told me that if it is a girl they want to name the baby after Diana. They discussed girls' names before George was born and now they're hoping the next one is a girl so they can carry out their wish to honour William's mother. They're not too thrilled at the thought it will be shortened to Princess Di. But it won't change their minds," Morton told The Sun.