Princess Leonor was the most supportive big sister at Infanta Sofia's confirmation in Madrid on Thursday.
The royal siblings were pictured holding hands as they arrived at church, with Sofia set to follow in Leonor's footsteps this summer as she starts her two-year International Baccalaureate at UWC Atlantic College.
See the Spanish royal family's arrival at the service in the clip below…
No doubt Leonor will have all the advice for her little sister as she prepares to move away from home this summer.
Leonor and Sofia are only two years apart in age and have often displayed their close sisterly bond, carrying out their first joint engagement together without their parents in 2021.
HELLO! takes a closer look at other royal siblings who share a close bond.
Prince George, Princess Charlotte and Prince Louis
The Wales children always look like they have fun together in public, with Princess Charlotte, in particular, being a doting big sister to little brother Prince Louis.
The Princess, eight, held five-year-old Louis' hand recently as they arrived at King Charles and Queen Camilla's coronation at Westminster Abbey, and appeared to keep a watchful eye on him at the service.
Princess Beatrice and Princess Eugenie
Eugenie shares an incredibly close bond with her big sister, Beatrice, with Eugenie proclaiming in an interview with The Telegraph in 2008 that: "Mummy, Bea and I call ourselves 'The Tripod', they are my best friends in the world."
The royal, who is expecting the arrival of her second child imminently, also pens personal tributes to Beatrice on special occasions such as birthdays.
Eugenie hinted that she has started her maternity leave as Beatrice visited a Chelsea Flower Show garden connected to one of her sister's patronages earlier this week.
The sisters also attended a coronation street party together earlier this month, with Eugenie quipping as she arrived: "I’m still waiting for my sister – I feel a bit weird without her."
Prince Archie and Princess Lilibet
The Duke and Duchess of Sussex's children have a two-year age gap between them and in November 2021, Meghan opened up about little Archie and Lilibet's sibling relationship for the first time on The Ellen Degeneres Show.
MORE: Prince Harry's sweetest father-daughter moments with Princess Lilibet
Ellen asked Meghan about her son Archie, saying: "Is he a good big brother?" to which the Duchess replied, "He loves being a big brother!"
She continued: "Someone told H (Harry) and I that when you have one kid it's a hobby, and two children is parenting. Suddenly we realised, oh right, everyone talks about what it's like for the second child, but no one talks about the adjustment for the first child when the second one comes along. So I think they have that moment of, 'Oh, this is fun...oh, this is how it is now'."
Ellen responded: "Well, he's sweet!"
Mia, Lena and Lucas Tindall
Mike and Zara Tindall's daughters, Mia and Lena, are doting big sisters to their baby brother, Lucas, who was born in March 2021. At the Burnham Market International Horse Trials, Mia was pictured helping to push the pram and holding little Lucas
King Charles and Princess Anne
The King and his younger sister were inseparable as children, and kept each other company while the Queen and the Duke of Edinburgh were travelling on royal tours.
The Princess Royal was given a starring role as Gold-Stick-In-Waiting at Charles's coronation, and rode horseback alongside the King and Queen's carriage during the procession.
In a rare interview ahead of the coronation, Princess Anne was asked what kind of King her brother will be.
"Well, you know what you’re getting, because he’s been practising for a bit, and I don’t think he’ll change," she shared.
“He is committed to his own level of service. That will remain true.”
Princess Catharina-Amalia, Princess Alexia and Princess Ariane
The Dutch royal princesses, who are close in age, are always pictured smiling and laughing together during their annual family photoshoots.
LISTEN: Royal editor Emily Nash on the coronation ceremony moment that took her by surprise
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