Family of an Indiana mom who died on a plane are still dealing with 'uncertainty'

The brother of Indiana mom Stefanie Smith, who died last week while flying home from vacation in the Dominican Republic, said Friday that they still don’t know what killed her.

“I’d say the uncertainty, the not knowing how she died, the not knowing when her body will be returned to us, has been the hardest thing recently,” Chris Volz told NBC News. “It’s been a week so we’re past the initial shock. But now, it’s the uncertainty.”

Volz said the family has picked out a tentative date for his sister’s “celebration of life,” but they still have no idea when the hospital in the Turks and Caicos will release her body and have not heard from American Airlines, the carrier Smith was flying on when she died Feb. 28.

"We are hoping to find out soon," Volz said.

The flight that Smith was on made an emergency landing on Turks and Caicos after the 41-year-old mother of two became ill. She was taken to the Cheshire Hall Medical Centre, where she died, according to The Royal Turks and Caicos Islands Police Force.

NBC News reached out to the hospital, whose spokesperson Daniel LeVin said the police are fielding all questions about Smith. The police have not yet responded to an inquiry from NBC News.

Volz said he was not aware of his sister, who lived in Danville, having any pre-existing health conditions. He said she was an avid exerciser who continued to work out even while on vacation with her boyfriend in the Dominican Republic.

"She also coached cheerleading and softball, when her kids were younger," Volz said. "She was very active. Right before she left, she took a picture with everyone and there was no indication that she was sick."

Smith had been on vacation in the Dominican Republic for five days when she and her boyfriend boarded a flight for Charlotte, North Carolina, where she was to take a connecting flight back to Indiana.

The young mom was sitting beside her boyfriend when she suddenly started going into convulsions, Volz said he was told.

"At 6:12 pm, the Police Control Room received a call from the Air Traffic Control Tower requesting medical assistance for a 41-year-old female, who at the time was receiving Cardiopulmonary resuscitation (CPR)," the Turks and Caicos police said in a statement posted on Facebook.

Joe Oyler, a firefighter from Wisconsin who was on the flight, told NBC News he heard the commotion at the back of the plane and volunteered to help when he learned a woman was having a medical emergency.

"But by then several people were already trying to revive her," said Oyler, adding that the plane crew appeared to have responded quickly to the emergency.

Volz said that his family has been struggling to come to grips with what happened.

"My sister was the kind of person who saw the best in everybody," he said. "She was very much into her relationships with her family, with her friends. She put smiles on peoples' faces."

This article was originally published on NBCNews.com