Oops! Kelly Rowland Accidentally Confirms Beyonce Is Having a Girl

 Kevin Mazur/WireImage.com

Hope Aunt Kelly's not in big trouble now with Sasha Fierce!

Kelly Rowland accidentally revealed the gender of pregnant Beyonce's baby-to-be to Us Weekly at the Cosmopolitan Awards in London Thursday night.

Rowland dished to Us about her Destiny's Child bandmate's pregnancy — and what she might get for the baby at the baby shower.

"I don't know," Rowland, 30, said, referring to the unborn child as "her." "I think her dad [Jay-Z] is gonna give her everything anyways, all I can give her is love."

Will the child of multimillionaires Beyonce and Jay-Z — who are reportedly building a 2,200 square-foot nursery at their NYC pad — be spoiled?

"I think she'll be very well behaved," Rowland replied, once again using the feminine "she. "Her parents will make sure of that."

(Indeed, a source previously told Us that Beyonce asked pals for pink Louboutin baby booties for her child, due in February.)

"Motivation" singer Rowland added that she gets a "weekly" update from her pregnant pal (who she's known since childhood) — and she's ready to babysit, thanks to Beyonce's younger sister Solange Knowles, who has a son, Julez. "I'm good with messy diapers," she joked. "Solange made me do Julez's messy diapers. I'm good with that."

Sign up now for the Us Weekly newsletter to get breaking celebrity news, hot pics and more delivered straight to your inbox!

Want stories like these delivered straight to your phone? Download the Us Weekly iPhone app now!