Authorities are investigating the death of an American woman on board a Princess Cruises ship on Tuesday.

The 52-year-old woman, described only as a "female guest" on the Royal Princess from the U.S., died under unclear circumstances. The ship was on a seven-day cruise from Fort Lauderdale, Florida, to Aruba.

The victim's brother, Tony Rodriguez, identified the woman to ABC News as American citizen Almarosa Tenorio.

“Almarosa was a very loving daughter, sister, mom and grandmother with a good heart," Rodriguez said in a statement. "Her passion was teaching and working with children. She had a vivacious personality with a smile that would light up a room. We are sad that she was taken from us at such a young age. She will be missed by all that knew her."

Tenorio lived with her son, a student at the University of South Alabama, according to a GoFundMe campaign set up for the family.

No cause of death has been reported, but her death was ruled unnatural, Aruba Public Prosecutor's Office spokeswoman Ann Angela told ABC News. The prosecutor's office will not be releasing the details of the autopsy.

The woman's husband was questioned as a witness and is not being investigated at this time as a suspect, Angela said.

Angela said the death is being investigated at every angle but would not disclose whether it's being considered a homicide.

"The incident was reported to the FBI and local authorities and the local authorities met and boarded the ship upon arrival in Aruba," Princess Cruises said in a statement Wednesday. "We are cooperating fully with the investigating authorities, including the FBI."

The ship, which can carry up to 3,560 passengers, was expected to return to South Florida on Saturday. The Royal Princess is set to undergo a $15.9 million makeover in just a matter of weeks.

"We are deeply saddened by this incident and offer our sincere condolences to the family and those affected," the cruise line said.

The woman's name and hometown have not been released.

The death was the second announcement of a person being killed on a cruise ship on Wednesday. Holland America announced a 70-year-old woman was killed when she fell into the water in the South Pacific while trying to move between deck and a smaller boat.

ABC News' Ben Gittleson and Darren Reynolds contributed to this report.