Penny Lancaster had a motherly glow on Wednesday evening at the Breast Cancer Care's 2010 Fashion Show in London and showed off her growing baby bump on the red carpet.

The child, due early next year, will be Rod Stewart's eighth and their second together. In August, the rock legend and his third wife announced she was expecting.

"We were thrilled and delighted to be able to tell Alastair that he was going to be the big brother to a little baby, expected just before Mummy's 40th birthday," the couple told PEOPLE.

Stewart and Lancaster wed in Portofino, Italy, in 2007.

Last year, Stewart told the British press that he and his third wife, 38, were hoping to add more children to his brood.