A north Texas woman accused of watching her boyfriend beat and stomp her 18-month daughter to death four years ago was found guilty of capital murder Friday, The Star-Telegram of Fort Worth reported.

Because she was 17 when her daughter, Tylea Moore, was killed on July, 4, 2014, Alexis Botello received an automatic life sentence, The Dallas Morning News reported.

Botello also was found guilty of tampering with evidence, according to Tarrant County court records.

Botello told authorities Tylea was killed by Joshua Beard, 24, at his home in Arlington, adding that he "didn't mean to," the Morning News reported.

According to court documents, Beard became enraged at the toddler and began yelling at her. He then hit the child, picking her up and calling her “a little demon” before throwing her onto a bed. Tylea fell off the bed, and Beard began stomping on the girl’s stomach until she vomited, police said.

Botello and Beard attempted to revive the girl after she stopped breathing, but she died at the home, the Star-Telegram reported. The couple then drove 40 miles with Tylea in the trunk of the car, the newspaper said. After stopping at a Walmart in Weatherford to buy shovels and gloves, Botello and Beard buried the girl in a shallow grave beneath a bridge in Poolville, the Morning News reported.

Prosecutors argued that while there was no evidence Botello had harmed her daughter, she had "legal duties to prevent what happened" and get medical help for Tylea, according to the Star-Telegram.

Beard was convicted of capital murder in April and sentenced to life in prison, the newspaper reported.