The mother living in a feces-filled Ohio house of horrors, where 16 “almost feral” children were found, got married at only 15 years old — just two months before giving birth to her first child.

Elizabeth Siders, 33, was legally married to Gary Siders Jr., who was 18 at the time, in 2008 in Mason County, WV, reported WSYX.

Two months later, she gave birth to the oldest victim in the case, a now-18-year-old who was rescued along with 15 others from a home in Vinton County, Ohio, according to records.

At the time, “there was no age minimum to marry in West Virginia,” and a 15-year-old could marry with the consent of their parents, said Amanda Alexander, a family lawyer in the Mountain State.

“The judge absolutely could have stopped this marriage,” but the law did not require the court to investigate, Alexander said.

Siders also reportedly gave birth to two further children — conjoined twins — who died at just a few hours old.

It is unclear how many of the 16 children are Siders’. Vinton County Prosecutor William Archer told a news conference Wednesday that he couldn’t confirm if all the children’s birth certificates had been found.

The lawyer representing Siders, Tommy Stolley, said that he believes she is the mother of all 16 children, who range in age from 17 months to 18 years old.

He is also looking into whether his client could be a victim herself.

“I think that this is more so a case of isolation than a case of evil, and I think that there’s an important distinction there,” he told the Associated Press.

“Because if that’s all you know — and you have to think someone at 15 years old doesn’t know a whole lot about being an adult, about being a mother, about being a wife — and that’s been your worldview for the past 17 or 18 years, you get shaped by that.”

Stolley said that Siders left high school after the 11th grade.

Ronnie Fletcher, who’s married to one of the grandparents’ adult daughters, told local news outlet WOWK 13 that she had a rough upbringing.

“She did not have a very good home life when they got together, and she escaped to Lynn [Christina] and Gary’s house, which … was back then a normal American home,” he said of her relationship to Siders Jr.

Meanwhile, in a Facebook post, a man identifying himself as Siders’ brother claimed his sister had been “indoctrinated” and said he had only recently reconnected with her after 15 years apart, Los Angeles Magazine reported.

He also referenced welfare and said “the state knows something” about his sister, but didn’t provide any evidence or further details supporting his statements.

The house in the small town of Hamden was plagued by years of horrifying abuse and neglect, according to authorities.

Conditions inside the feces-strewn house were described as “horrific” by authorities, with the situation investigators encountered “pure evil,” according to Ohio Attorney General Andy Wilson.

Siders is one of four family members charged in the investigation, including her husband and her in-laws, Gary Siders Sr. and Christina Siders.

They collectively face 68 felony child endangerment charges, with all 16 children allegedly suffering serious physical harm, according to prosecutors.

All four have pleaded not guilty and remain jailed on $300,000 bond.

Prosecutors said that Siders Sr. had been released from jail on a recognizance bond after suffering a medical episode.

Upon inspection by doctors, it was discovered that the father-in-law has a serious medical condition that needs care.

If he is released from the hospital, he will have a GPS tracker, and competency motions have been filed for him, Archer said.

The 16 children were removed from the home and placed in the temporary custody of the Ohio Department of Job and Family Services.

The investigation remains ongoing, with additional evidence and possible extra charges emerging in the coming weeks, according to prosecutors.

With Post wires