'She didn't deserve this,' say parents of pregnant cheerleader allegedly stabbed to death by football player

Aaron Trejo, 16,is charged as an adult in the stabbing death of a pregnant girl.

The parents of a pregnant Indiana cheerleader who was allegedly murdered by her unborn baby's father are still in shock over their daughter's sudden death, they told ABC News.

Dave Roushselang and Nicole Rouhselang, the father and stepmother of 17-year-old Breana Rouhselang, who was stabbed to death over the weekend and left inside a dumpster near her mother's home, described her as a "very sweet, very beautiful young lady" who "wanted to be everyone's friend."

"She's the nicest, sweetest, most innocent girl you'd ever meet," Dave Roushselang said.

Dave Roushselang said he was still trying to wrap his head around his daughter's death.

"We’re just in shock, really. We’re in disbelief that this is going on," Nicole Rouhselang said. "I woke up this morning and wanted to send her a text. But, there’d be nobody on the other end."

The couple did not know Breana Rouhselang was pregnant and didn't know the boy accused of killing her, they said.

"We didn't know anything about it," Dave Roushselang said.

When asked if they are seeking justice, Nicole Rouhselang replied, "Yes. It needs to be served."

"She didn't deserve this," the stepmother said. "Nobody deserves this."

Aaron Trejo, 16, a football player at Mishawaka High School, pleaded not guilty Tuesday to murder charges for Breana Rouhselang and her unborn child.

Trejo is charged as an adult in the death of his classmate, who was six months pregnant. Her body, stabbed multiple times, was found in a dumpster near her home in Mishawaka, Indiana.

Trejo was arraigned Tuesday afternoon via video conference in St. Joseph County Superior Court in South Bend and pleaded not guilty to one count each of murder and feticide.

Trejo listened calmly as a judge read the charges against him before asking him to enter his plea.

The judge ordered that he be held in jail without bond pending a Dec. 19 hearing.

Trejo allegedly admitted to investigators that he stabbed Rouhselang in the heart with a knife Saturday night after they argued over her pregnancy, according to a charging document.

He allegedly told police that he went to Rouhselang's house with the knife "because he thought it would kill Breana quickly," according to the charging document.

"I took action....I took her life," Trejo allegedly told police, the affidavit states.

Roushelang's mother woke up around 1 a.m. Sunday and became concerned when she didn't find her daughter at home, according to the court documents. She went to Trejo's home several blocks from her house, but Trejo said he didn't know of Breana's whereabouts.

The mother then called the police to report her daughter missing, police said.

An autopsy determined that Breana died from multiple stab wounds and that she had been strangled with her own scarf.

Trejo allegedly told detectives that he planned for a week to kill Breana because she had waited to tell him about her pregnancy until it was too late for her to get an abortion, according to the charging document.

The family has set up a GoFundMe account to pay for the "proper funeral" that Breana Rouhselang deserves, they said.

"Nobody expects anything like this to ever happen," Dave Roushselang said. "A lot of people don’t have funds set aside. You don’t expect something like this to happen to anybody, especially a 17-year-old girl."

ABC News' Rachel Katz, Whitney Lloyd and Alex Perez contributed to this report.