The tragic story of a dying woman who killed her disabled daughter.

Profoundly disabled with cerebral palsy, Courtney could not walk, talk or care of herself. Her needs were so great that, by the age of five, she had already been abandoned by her own mother and an adoptive family. Then along came Bonnie Liltz.

For 23 years Bonnie was there. A devoted carer, loving single mother and constant companion to Courtney. Until she killed her.

One morning in May 2015, overcome by the pain of her ongoing health problems and believing she was near death, Bonnie emptied a lethal dose of medication into Courtney’s feeding tube before taking some herself, washed down with a glass of wine, reports The Chicago Tribune. She recovered. Courtney did not.

According to authorities, the 56-year-old left a suicide note that read, “I’m so sorry to put you all through this but I can’t leave my daughter behind… I am having difficulty breathing now. If I go first, what will happen to her? I don’t want her to live in an institution for the rest of her life. She is my life.”

Having plead guilty to involuntary manslaughter, the Illanois woman was this week sentenced to four years in prison, far exceeding the prosecution’s recommendation of probation and mental health counselling, but well below the maximum 14-year penalty for the charge, The Chicago Tribune reported.

“What you did that morning was not an act of love, it was a crime,” said Cook County Judge Joel Greenblatt during sentencing. “Life is precious… even life that is profoundly disabled. Your daughter, Courtney, was innocent, vulnerable and fragile.”

Bursting into tears, Liltz’s bond was revoked and she was immediately taken into custody. She, her family and friends now believe she may die there.

Liltz suffers from chronic bowel and bladder problems that stemmed from treatment she underwent for ovarian cancer at the age of 19. She was then reportedly hospitalised for skin cancer treatment in 2012, leaving Courtney to be placed in a residential care centre – an experience that has haunted Bonnie ever since.

In court, she described the ongoing horror and shame she experienced after discovering her daughter unwashed and wearing a soiled nappy. She vowed that it would never happen again – a vow that proved fatal for the 28-year-old.

“The thought of her having to live in an institution was more than I could bear,” Liltz said on the stand last week. “The only place I thought she would be safe and happy was in heaven with me.”

Her lawyer plans to appeal.