"You can't hold somebody responsible for the rest of their life for something they did when they were 12," Angie Geyser told The Milwaukee Journal-Sentinel in an interview published last week.
This is the first time she has commented publicly on the case since her daughter, Morgan, was charged with attempted intentional homicide for the May 2014 stabbing of Payton Leutner, then 12. Morgan and her friend Anissa Weier, both also 12 at the time, are accused of luring Payton into the woods and stabbing her 19 times with a kitchen knife, leaving her to die.
Payton survived after being rushed to the hospital with life-threatening injuries.
"I don't think that there were any glaring, obvious clues that she was ill," Geyser said. "She was just always such a gentle and kind person."
A forensic psychologist testified for the defense at a June 2015 hearing that Morgan’s father, Matthew Geyser, was hospitalized at least four times as a teenager because of mental illness and later went on disability because of his schizophrenia, according to the Journal-Sentinel.
Prosecutors have said that Weier and Geyser, both from Waukesha, Wisconsin, were obsessed with the character Slender Man, who is often depicted in fan fiction stories online as a horror figure who stalks children.
Not-guilty pleas have been entered on behalf of both teens.
A Waukesha County Court judge ordered the defendants to be retained in the adult jurisdiction, which could send them each to prison for up to 65 years.
Geyser is fighting to get her daughter's case tried in the juvenile court, where the maximum sentence for Morgan would be three years in a juvenile prison. A 2nd District Court of Appeals panel in Waukesha is deciding whether to move the case to juvenile court.
Earlier this month, Morgan was moved from a juvenile detention center in Wisconsin to a state mental hospital. Geyser said the treatment that Morgan is receiving there is helping her daughter but also making her more aware of her road ahead.
"With this lucidity that she's developed comes an awareness of the gravity of her situation, so she misses home, she misses her family," Geyser told the Journal-Sentinel.
The other suspect in the case, Anissa, remains behind bars at the juvenile detention center on $500,000 bail.
A representative for the victim's family told ABC News the Leutners "fully support" prosecutors' efforts to try Anissa and Morgan as adults.
"If tried as juveniles, there is a likelihood that both assailants would already have been released, with little to no supervision, and their records expunged," the representative said in a statement on behalf of the family. "Our little girl was lured into the woods by these two assailants and brutally stabbed 19 times. Their premeditated attack was with the hope of killing our daughter. We fully support the efforts of the district attorney in this case. We must protect our little girl and others so this never happens again."
An attorney for Geyser told ABC News in a statement, "We remain optimistic that the court of appeals will issue a decision sending the case to children's court. Until that occurs, Morgan will unfortunately be held in custody with limited access to her family."
Anissa's attorney told ABC News in a statement that his client is "awaiting a decision from the court of appeals" and that the next court date in the case is scheduled for July 15.