As a family of four, they feel they are on the brink of "exciting times," the friend tells PEOPLE.
Credit: Suzanne Plunkett/Reuters/Landov

As they settle into life at their country home of Anmer Hall, Prince William and Princess Kate have the family life they’ve always wanted.

As a family of four, they feel they are on the brink of “exciting times,” a friend tells PEOPLE.

And this “golden period” of their lives extends to all members of the royal family.

“The Queen and Prince Philip and Prince Charles are absolutely delighted they have a grandchild and great-grandchild – and of course it is an heir and spare,” says the pal.

But don’t expect William and Kate to stop at two.

“They’ve been looking forward to having a family,” the friend says. “They enjoy family life and seeing it among their friends’ families – that’s why I think they will have a third.”

The proud parents are ready for a summer of bonding with their children at their country mansion, which sits on Queen Elizabeth’s vast Sandringham estate. Anmer Hall, which is 110 miles north of London, is also close to Cambridge, where William will resume his training for his new air ambulance job on June 1.

Kate will take more time off from official duties than she did last time and she is not planning on adding any extra help.

She has told friends that she believes she came back into the public eye too early after Prince George was born. She wants to have that “mother time” and enjoy it with her children.

For much more on Princess Charlotte’s first days at home with William, Kate and big brother George, pick up this week’s issue of PEOPLE, on newsstands Friday