During an interview with BANG Showbiz she let the secret slip.
"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 spoiled 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!"