Robin Gibb's widow admits news the couple's son is expecting his first child is bittersweet.

The Bee Gees legend passed away last May after losing his battle against cancer and while Dwina is thrilled Robin-John - also known as RJ - and his girlfriend Megan Golub are having a baby, she is sad Robin won't be around to see the tot.

She said: ''When I lost Robin I wasn't expecting this. It's absolutely wonderful. Robin's mum Barbara is known as Nana Barbara, so I'd like my grandson, or granddaughter, to call me Nana Dwina. I can't wait to paint and draw for the little one.

''To welcome in 2013, we all went outside and wrote Robin's name in the sky with sparklers. I was thrilled about the baby, but sad that Robin wasn't with me to share the happiness.''

Dwina says Robin would have made an excellent grandfather as he was so good with RJ when he was growing up.,

In an interview in Britain's HELLO! magazine, she said: ''He loved children. Grandchildren would have found him hilarious because he had a great sense of humour and made everything fun. When RJ was little, Robin would dress up as Father Christmas, with pillows stuffed into his red tunic and make up strange names for the reindeer.

''He'd also transform himself into imaginary characters and enact little sketches. One day he and RJ turned the sitting room into a Civil War battlefield. He was passionate about history and would have made an excellent teacher. He would have relished his role as a grandfather and been brilliant at it.''