The founder of GP Nutrition explained that Mr Mapelli’s son, Wolfie – from a previous relationship – will be happy to welcome a baby sibling.
She told Hello!: “I couldn’t be happier for them, it is so exciting. They are both amazing with children and it will be so lovely for Wolfie to have a baby brother or sister.
“They are so happy together and now they are finally married. It’s funny how that changes the dynamic.
“Even though they were wonderful together before, they are a proper family now.”
Princess Beatrice and her husband announced they were expecting their first child on May 19.
Buckingham Palace released a statement to say, “Her Royal Highness Princess Beatrice and Mr Edoardo Mapelli Mozzi are very pleased to announce that they are expecting a baby in autumn of this year.”
“The Queen has been informed and both families are delighted with the news.”