The Duke and Duchess of Sussex’s royal relatives and friends will be on hand ready to help, guide and support – and play with – the new addition to the family.
Here’s a look at who will influence Harry and Meghan’s baby:
George, Charlotte & Louis
Living close by together at Kensington Palace, Prince George, Princess Charlotte and Prince Louis are likely to spend a great deal of time with their new baby cousin.
Harry and Meghan’s baby boy or girl will enjoy playdates with the Cambridge youngsters, join them on the Palace balcony for Trooping the Colour, and spend summers together at Balmoral and Christmases at Sandringham.
Charlotte – described by Kate as being feisty – is known for her confidence in front of the cameras, while future king George – who loves all things to do with helicopters and the police – is more shy in public.
The Duke and Duchess of Cambridge
Experienced three-time parents William and Kate will be able to offer advice to Harry and Meghan on everything from sleepless nights, feeding and weaning to tantrums and choosing the right school.
Kate will be able to help Meghan on how best to balance motherhood with royal duty, and the ins and outs of taking your children on a royal overseas tour.
William, who, according to Kate, initially found it difficult adjusting to parenthood, will be able to offer support to younger brother Harry as he becomes a father.
Meghan’s mother Doria Ragland proudly watched her only child marry into the royal family in the grand surrounds of St George’s Chapel, Windsor, in May 2018.
Meghan and her mother, Doria Ragland, arriving at Cliveden House Hotel on the eve of the royal wedding (Steve Parsons/PA)
She was the only member of the former actress’s family who attended, and at one stage took the Prince of Wales’s arm as they left the ceremony.
Meghan is close to her mother and will want Ms Ragland to pass on the life lessons she taught her to her own child.
Writing on her lifestyle blog, Meghan told how her “free-spirited clinical therapist” mother took her to visit the slums of Jamaica and to see poverty in Mexico when she was just 10.
My mother raised me to be a global citizen, with eyes open to sometimes harsh realities,” she said.
Ms Ragland has kept her daughter’s counsel despite the press interest.
Harry has paid tribute to the Queen’s “incredible” sense of duty, and Meghan demonstrated her rapport with the monarch when they carried out joint engagements in Chester in June 2018.
The baby will be the Queen’s eighth great-grandchild.
The Prince of Wales
Harry’s father Charles is said to have forged a strong bond with Meghan, and walked her down the aisle through the Quire when her father pulled out of attending the wedding.
A doting grandfather, the prince will want to pass on his love of the outdoors and the natural world to his new grandchild, and read him or her the stories he enjoyed as a child.
Kate with George and Charlotte and Autumn Phillips and her children, Savannah and Isla, at the Beaufort Polo Club in Tetbury (Steve Parsons/PA)
Days will also be spent at the polo with Peter and Autumn Phillips’ fun-loving children Savannah and Isla, and Zara and Mike Tindall’s cheeky daughter Mia and her younger sister Lena – who will be the new royal baby’s second cousins.
Zara and Mike Tindall’s daughter Mia with her cousins Savannah Phillips and Isla Phillips at the Gatcombe Horse Trials (Steve Parsons/PA)
Meghan’s stylist and best friend Jessica Mulroney will also play an important part in the baby’s life.
She supported Meghan in the difficult days leading up to the wedding amid the turmoil caused by the absence of her father Thomas Markle.
Mrs Mulroney’s children – twin boys Brian and John and daughter Ivy – were pageboys and bridesmaid.
She is married to Ben Mulroney, the son of former Canadian prime minister Brian Mulroney.
The duchess’s close friend Benita Litt runs her own brand agency and helps others to start businesses.
Meghan has spent Christmas with the Litt family in the past.