Sept. 11 (UPI) — Princess Astrid of Norway died on Friday at the age of 94, two days after the funeral for her younger brother, the late King Harald V.

The princess’ last public appearance was at Oslo Cathedral on Wednesday, where she paid her respects at the funeral of King Harald.

Princess Astrid served as first lady when she was 22 after the death of her mother, Crown Princess Martha, in 1954. She remained in that role until her brother married in 1968.

“Aunt Astrid was an important source of support for King Harald and the rest of our family,” King Haakon VIII said in a statement. “We learned a great deal from her, and she was never afraid to speak her mind.”

“Her passing is a great loss to us,” the new king added. “We will miss her.”

King Haakon said his aunt had “an infectious sense of humor.”

“In her work, Princess Astrid was always particularly concerned with care and inclusion for the most vulnerable in society,” the king added.

In March, Princess Astrid received treatment for pneumonia. Her cause of death was not disclosed.

King Haakon said the Royal Palace’s flag would be flown at half-staff on Friday and on the day of his aunt’s funeral.

King Harald’s funeral was held at Oslo Cathedral on Wednesday, and drew a large crowd of royals and dignitaries from around the world.

The late king, 89, died at Oslo University Hospital Rikshospitalet on Aug. 28.