The youngster took centre stage when the monarchy's website was relaunched last year
Until now the cherubic daughter of Crown Prince Felipe and Princess Letizia has been kept largely out of the spotlight by her protective parents. They allow the occasional photograph of their daughter, who is known by the title Infanta Leonor in her home country to differentiate her status as a princess by birth not marriage.
The little girl is sometimes pictured attending church and at photocalls for their summer holiday with her younger sister Sofia.
A fortnight ago, the royal duo tweeted pictures of themselves on the school run with their daughters. The images marking the tenth anniversary of their glittering wedding showed them as a modern, down-to-earth family.
Letizia, a former TV journalist, has been especially keen to give the princesses the kind of private, normal childhood that eluded her husband. This will now change to a certain degree.
Leonor is set to become the Princess of Asturias on her father's accession
When the prince is crowned Felipe VI, a ceremony which will probably take place within the month, Leonor will assume the title The Princess of Asturias, a similar role to the Prince of Wales. According to the Spanish constitution, she will eventually become queen unless her parents have a son.
Her investiture as the Princess of Asturias will not take place until her coming of age, with her swearing to discharge her duty before Parliament just as her father did before her. The times have changed since that day on 30 January, 1986 - only ten years after the end of the dictatorship - when the monarchy was a vital symbol of national unity.
"The political situation meant that Felipe was much more exposed to the public," says one royal expert. "It was important to show the role of the Crown. Letizia is much more protective of her daughters than [her mother-in-law] Queen Sofia. Their public appearances will be rationed but they will have to be seen more and will accompany their parents to some official engagements."
The royals present a modern lifestyle, taking their daughters to school themselves
For now, the youngster will keep on with her studies at Santa Maria de los Rosales school, where she was enrolled in 2008. Leonor takes classes in Chinese and English, a language she also speaks with her nanny.
In the years to come the Infanta will also receiving training in public and military affairs in preparation for her future role as head of state.