Dr. Eithne Walls was vacationing in Brazil with two friends -- also doctors -- and boarded the plane Sunday night after a reunion with other former medical students.
The father of one of her friends said he thought they were scheduled to be on the Monday flight out of Rio de Janeiro, but when he went back to open his deleted e-mails, "a nightmare opened up as well."
Walls joined "Riverdance" in 1998 as a member of the Flying Squad, then joined full-time for an 18-month run at Broadway's Gershwin Theatre.
Several years later, Walls returned to her native Ireland for the production's first run at Dublin's Gaiety Theatre.
"She always had a smile on her face and she just seemed to be always happy and enjoying life," a "Riverdance" official said in a statement released today.
"Eithne, we will miss your easy smile," her parents and siblings said in a statement. "We will miss your dancing feet. Her friends will, we hope, remember their special time together with fondness and joy, despite its tragic end."
Walls, who left dancing to pursue medicine, had just started a new job at an eye, ear and throat clinic in Dublin.
The Paris-bound jetliner disappeared over the Atlantic Ocean after taking off from Rio de Janeiro, Brazil, Sunday. Debris was found floating in the middle of the ocean Tuesday. There were no signs of life. A total of 228 people were aboard the plane. Two Americans -- Michael Harris, 60, and wife Anne, 54 -- were on the plane, their employer, Devon Energy, said.
Also aboard the doomed flight was Pedro Luis de Orleans e Braganca, 26, a direct descendent of Brazil's royal family, which was overthrown in 1889.