Kate Middleton so lonely without mum Carole
Kate Middleton has become very close to Prince William's stepmum, Camilla
Prince William will return to his duties in the RAF after the birth
Prince William told the Queen about the pregnancy when Kate Middleton was admitted to hospital
Camilla will be offering Kate Middleton parenting advice
But when Carole can't be by her pregnant daughter's side, she knows Kate has Camilla, Duchess of Cornwall for support.
'Kate spends hours each week calling her mum,' says our source. 'She gets lonely without her, so it's nice for Carole to know Kate's got Camilla.'
In fact, we can reveal the two are so close, Camilla, 65, knew about Kate's pregnancy before the Queen.
Prince William, 30, told his gran when Kate, 30, was rushed to hospital suffering extreme morning sickness on 4 December.
But our source says: 'Camilla was the first outside of Kate's immediate family to know.'
Camilla's help will be all the more important as Wills is expected to return to work as an RAF Search and Rescue pilot in Anglesey soon.
Read more about Kate Middleton in Now magazine dated 31 December 2012 - out now!