The Norwegian Royal Family turned out in Oslo together on Saturday (17.05.08) to witness the Constitution Day festivities.
The four-year-old princess delighted onlookers by showing off her playful side by putting her hand over mother Mette-Marit's nose and mouth.
Ingrid Alexandra is the country's first-ever female heir to the throne.
She has a younger brother, two-year-old Sverre Magnus and a 10-year-old stepbrother, Marius, from Mette-Marit's previous relationship.
Constitution Day is Norway's national day and a public holiday. It marks the signing of the constitution in 1814, which saw Norway recognised as an independent nation.