The Princess of Wales is celebrating her nephew Arthur Matthews' 6th birthday on Tuesday, a special occasion that is sure to bring the Middleton family together.
The family birthday comes shortly after Kate, 42, revealed she has completed chemotherapy.
The Princess shares a close bond with her younger siblings, Pippa Matthews, 41, and James Middleton, 37, and is a doting aunt to Pippa's three children and James' son Inigo.
Pippa and her hedge fund manager husband James Matthews are parents to Arthur, Grace, three, and two-year-old Rose, and live on a sprawling estate in the Berkshire countryside.
The sisters live in the country of Berkshire, west of London, with Pippa and her husband Matthew living close by to Carole and Michael Middleton, and her younger brother, James Middleton and his wife, Alizee Thevenet.
Meanwhile, Prince William, Kate and their three children, live at Adelaide Cottage in Windsor – a short drive away from Kate's parents and siblings.
The younger Middleton generation are all very close – with James opening up about his nieces and nephews in the My Saturday column in The Telegraph, and gushed how they dote on his one-year-old boy.
"We'll often stop at my parents' house for tea or supper," he revealed. "My sisters and I are all within 30 minutes' drive, so there is often an aunt or a cousin passing through, too.
"The cousins all play their role in looking after Inigo – there's seven of them altogether at the moment. I think they're all impressed at how much of a mess Inigo can make. But there's lots of laughter and giggles about."
In his new memoir, Meet Ella: The Dog Who Saved My Life, Kate's younger brother shared sweet details into his upbringing – and offered plenty of insight into life with his sisters.
Ahead of the release, James opened up to HELLO! and revealed how he took parenting advice from his sisters Kate and Pippa.
"It's been wonderful, seeing them become mothers and being so dedicated and strong. I'm in awe of that," James said, before quipping: "I've been fortunate to see how my sisters have done it and take tips along the way – some I take on board, and others I'm like: 'Hmm.'"
Of borrowing the children's hand-me-downs for his own son Inigo, he added: "They are milestones, because [my sisters] remember when their child was wearing something, and how old they were – it takes them back. It's been a lovely thing for them."