Although the 'Down for Whatever' singer is struggling to come up with a suitable baby shower gift for her former Destiny's Child bandmate - who is expecting her first child, a daughter, with husband Jay Z - she has already agreed to be on hand for babysitting duties.
Kelly told BANG Showbiz: "I'm so happy for my sister and her husband. They're so happy In This Moment right now, as they should be. They've made a little bundle of love, I'm so excited for them.
"I have no idea what I'm going to buy Beyonce at the baby shower because Jay is going to buy that little girl every single thing possible. She won't be spoilt but she will be very well looked-after.
"I'll be on hand for babysitting duties and I'm actually very good with messy diapers!"
Kelly won the Ultimate TV Personality prize at the Cosmopolitan Ultimate Women of the Year Awards 2011 in London last night (03.11.11).
She looked radiant as she walked down the red carpet at the event at the Banqueting House in a floor-length Pink gown.
Speaking after the ceremony, Kelly admitted she isn't feeling broody herself, and will just be "borrowing" her friends' babies to play with instead.
She said: "I'm not broody - I have five friends who are pregnant right now and so I will be borrowing their babies to play with."
Other winners on the night included Jessie J, who took home the Ultimate Music Star award, model Daisy Lowe, who bagged the Ultimate Style Queen accolade, and Blondie's Debbie Harry, who was named Ultimate Icon.
COSMOPOLITAN ULTIMATE WOMEN OF THE YEAR AWARDS 2011 FULL LIST OF CELEBRITY WINNERS:
Ultimate Theatre Star Â
Ultimate Music Star
Ultimate TV Actress Â Â Â Â Â Â Â Â Â Â Â Â
Ultimate TV Personality
Ultimate Celeb Men of the YearÂ Â Â Â Â Â Â Â Â Â Â
Ultimate US TV Actress
Ultimate Film Star
Ultimate Style Queen Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â
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