The stepgrandmother who helped raise Timothy Hudson, the 16-year-old accused of sexually abusing and killing his stepsister Anna Kepner, wants the teens’ father to be charged for allowing them to drink and share a room on the fatal cruise trip.

Sonya Ziske defended Hudson — telling CBS News she “100%” believes “that alcohol” and “missing meds have everything to do” with the alleged murder, which Hudson insists he has no memory of.

She instead wants Hudson and Kepner’s father, Christopher Kepner, as well as his wife, Hudson’s mom Shauntel Kepner, to face charges for what she called their “lack of parental supervision on a floating city that is usually like Sin City.”

“Not giving medication, or making sure you have the medication before you leave, and the drinking and putting three teenagers — two boys and a girl — in a room together that were not raised together,”  she told CBS News. 

“It’s just a recipe for disaster.”

Kepner, a bubbly, 18-year-old high school cheerleader, was found dead wrapped in a blanket and life jackets under her bed while on a Caribbean Carnival Cruise with family members in November in a cabin where she and Hudson had been rooming together on the six-day vacation. 

Officials determined that Kepner was strangled and had been sexually assaulted. Hudson was charged with her murder — first as a juvenile and then as an adult.

Ziske — Shauntel Kepner’s stepmom — helped raise the accused killer, and denied reports that he was “raised to think of [Anna Kepner] as a sister.”

Hudson told his family that he has no memory of what happened, and Ziske “absolutely” believes it was due to a mixture of his medication — or lack of it — and booze. She said his story has remained consistent.

“He truly does not remember,” Ziske said. “Timothy has said that they were drinking. I believe 100% those kids were drinking on the ship.”

“He did not change from all the interviews that he has had. He has not changed what he has said at all. If there was any type of memory there, he wouldn’t be able to say the same exact thing,” Ziske insisted.

Shauntel and Chris Kepner have previously denied the children were drinking through their attorney during a family court hearing related to a custody battle, according to CBS News.

Shauntel Kepner’s attorney, Millicent Athanason, told a previous hearing that “there are videotapes on the ship that confirmed that there was absolutely no drinking.

Hudson has pleaded not guilty to the charges and, despite being charged as an adult, a federal judge has allowed him to stay with maternal uncle ahead of his trial.

Ziske claimed Christopher and Shauntel Kepner are unfit to have custody of the remaining children after Anna’s death on the cruise ship.

Shauntel “kept them isolated from everybody over here. From their dad, from their grandparents. From all of us,” Ziske said. “So, I don’t know the past two years. Like, if he was angry, or his mental state, I don’t know any of that.”

CBS News said an attorney for Chris and Shauntel Kepner did not respond to a request for comment.