But the doctor did receive her second wish, as the video was viewed more than a million times on Facebook and picked up by news outlets around the country. Dr. Gaudry did not immediately return phone messages requesting an interview Tuesday morning.
The attention her video received underscored the ongoing controversy around the national anthem following Mr. Trump’s repeated criticism of N.F.L. players who have knelt during performances to call attention to police violence against black people.
In response to questions about the doctor’s video, the airline said that a Delta honor guard, a group of employees, many of whom are veterans, volunteer to greet every plane that carries a fallen soldier at the airport in Atlanta, as well as those in Salt Lake City, Los Angeles and Washington.
“The ceremony is somber and dignified,” said a Delta blog post from 2016, describing the tribute. “The coffin is pulled from the aircraft, while flags from all five military branches are displayed behind a military escort.”
Dr. Gaudry said that the plane’s captain had announced that the flight from Philadelphia was carrying a fallen soldier, Army Staff Sgt. Dustin M. Wright, 29, who was one of three soldiers killed in an ambush in Niger earlier this month. A fourth soldier was later found dead.
The captain asked that the other passengers remain seated while the coffin, which had been accompanied by another soldier on the flight, was taken off the plane by an honor guard.
Dr. Gaudry said that she had been inspired to sing “The Star-Spangled Banner” as the soldier left the plane and the coffin was carried out. She asked other passengers to do the same, and some agreed, she said.
As the plane started to descend, she said on the video that a flight attendant told her that it was against company policy to proceed with the singing.
A second announcement was made, asking that passengers be quiet as the soldier left the plane to accompany the coffin, Dr. Gaudry said. The announcement did not mention that singing the national anthem was against company policy.
“We all sat in silence as the honor guard took the soldier off the plane,” Dr. Gaudry said.
Dr. Gaudry told Fox News that Delta had called her to apologize and that Sergeant Wright’s family had also called, to thank her.