The royal teen gives a subtle smile in the snap, showing off her freckles and wearing her hair loose
Credit: Julia Naglestad, the Royal Court

Happy birthday, Princess Ingrid Alexandra!

The heir to the Norwegian throne celebrated her 15th birthday on Monday, and the royal family marked the occasion by releasing a close-up portrait shot by photographer Julia Naglestad. The daughter of Crown Princess Mette-Marit and Crown Prince Haakon – and granddaughter of King Harald V and Queen Sonja – gives a subtle smile in the snap, showing off her freckles and wearing her hair loose.

“15 years today! Congratulations on the day, Princess Ingrid Alexandra,” reads the photo’s Instagram caption.

The royal is currently second in line to the throne, behind her father. Last year, she met Kate Middleton and Prince William when the British royal couple visited Norway.

Prince William and Catherine Duchess of Cambridge visit to Norway - 01 Feb 2018
Kate Middleton and Princess Ingrid Alexandra
| Credit: Tim Rooke/REX/Shutterstock

For Christmas, the Norwegian royals released a series of family photos. Ingrid Alexandra posed alongside her parents, grandparents and younger brother, 13-year-old Prince Sverre Magnus, in front of a decked-out Christmas tree at the Royal Palace in Oslo.

Princess Ingrid Alexandra, King Harald, Crown Princess Mette-Marit, Crown Prince Haakon, Queen Sonja and Prince Sverre Magnus
| Credit: Hakon Mosvold Larsen/AFP/Getty

Prince Haakon and Princess Mette-Marit also took the opportunity to pose for a more intimate photo with their kids. Haakon rests his arm on Prince Sverre Magnus’s shoulder, and both the father and son look dapper in suits and ties. Princess Ingrid Alexandra opted for a dark turtleneck and skirt with tights, while her mother sported a cozy white sweater and flowing black skirt.

Princess Ingrid Alexandra, Crown Princess Mette-Marit, Crown Prince Haakon and Prince Sverre Magnus
| Credit: Hakon Mosvold Larsen/AFP/Getty

The cheerful photo comes just months after Crown Princess Mette-Marit, 45, announced that she has been diagnosed with chronic pulmonary fibrosis, which occurs when lung tissue becomes scarred and causes reduced oxygen supply in the blood. There is currently no way to reverse or slow down the damage to the lungs.

“For a number of years, I have had health challenges on a regular basis, and now we know more about what these are in,” Mette-Marit said in a statement. “The condition means that the working capacity will vary. The Crown Prince and I choose to inform about this now, partly because in future there will be a need to plan periods without official program. In connection with treatment and when the disease is more active, this will be necessary.”

The disease is caused by a number of factors, but the Royal Court’s statement said that it’s “not yet clear” if Princess Mette-Marit’s condition “is linked to a more extensive autoimmune disease process or if there are other causes that underlie the lung changes.”

Crown Princess Mette Marit Presents The Nordic Council Literature Prize 2018
Prince Haakon and Princess Mette-Marit
| Credit: Rune Hellestad/Corbis/Getty

Princess Mette-Marit was a single mother of a son, Marius Borg Høiby, 22, when she married Crown Prince Haakon, the first in line to the Norwegian throne after his father, King Harald V.