Anna Kepner's Grandparents Say They 'Cannot Fathom' Why Someone Would Hurt Her as Stepbrother Is Reportedly Considered 'Suspect'

The grandparents of Anna Kepner, the Florida teenager who died aboard a Carnival cruise ship, are sharing new details surrounding her death.

Barbara and Jeffrey Kepner were traveling with their 18-year-old granddaughter Anna, her father, stepmother and stepsiblings on the Carnival Horizon cruise ship when she was found dead on Nov. 8, ABC News reported.

“We were all having a great time," Barbara Kepner told the outlet. "I couldn't fathom why anyone would wanna hurt my baby."

Anna’s body was discovered under a bed in the room she had been staying in with her two stepsiblings, CBS News previously reported. Her stepbrother is now being considered as a suspect in her death, her grandparents told ABC News. Other outlets, including CBS News, previously reported that the stepbrother is a suspect, but cited court filings in an unrelated case involving the stepmother.

“In his own words, says he does not remember what happened,” Barbara told the outlet. “I believe, to him, that is his truth. He was an emotional mess. He couldn't even speak. He couldn't believe what had happened.”

According to the grandparents, per ABC News, the Kepner family was told by authorities that the stepbrother was “the only one seen going in and the only one seen going out” from the room he was sharing with Anna.

Barbara described Anna and her stepbrother as “just like brother and sister” and that she and her two older stepsiblings “wanted to stay in the room together” on the cruise ship.

“I know that those two kids cared about each other in the right way,” she said. “I can't accuse him because I don't know what happened in that room.”

Following her death, Anna’s stepbrother was hospitalized for psychiatric observation after returning to Miami, before being released to stay with a family member, Anna's grandmother told ABC News.

Barbara said she last saw Anna alive the previous night at dinner, after she told her she “didn’t feel well,” she told ABC News.

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“She must have felt better, because she got dressed up. And she came down, we were playing in the casino,” she recalled. “And she sat down … and she said, ‘Meemaw, I love you guys, I'll see you later.’ She'd pop in and out to check in with us. And we never saw her again after that.”

The family was notified of a medical alert through the ship’s loudspeakers the following morning. “I knew when [my husband] walked in the room, something was wrong … I just screamed,” Barbara told ABC News.

The FBI informed Anna’s family that her cause of death was asphyxiation, her grandparents confirmed to the outlet. Anna's grandmother said that they were told that she had been put in a “bar hold,” a maneuver where an elbow is placed across the neck, but a formal cause of death has not been officially announced by authorities as of the time of publication.

No arrests have been made at this time. PEOPLE reached out to the FBI for further comment, but they did not immediately respond.