The body of 17-year-old Libbi Toledo was found at a scrapyard in Kircaldy in September after she had been reported missing.
The teenager had autism and ADHD, as well as severe mental health issues.
Speaking to the BBC, Libbi’s mother Judi said the manner in which her daughter was “let down by the system is absolutely disgusting”.
She added: “If she had got the help she needed then, maybe she would still be here.
“We can’t guarantee that but maybe I wouldn’t have had to plan a funeral last month”.
Libbi had been in ‘secure’ residential accommodation three or four times over the last three years but Judi believes this was inadequate.
She added: “Secure accommodation is never good enough for people who need to be in a psychiatric hospital.
“I don’t think any parent should have to fight to get appropriate health care for their child. Kids are not getting the help they need.”
Libbi was assessed by Child and Adolescent Mental Health Services (CAMHS) each year from the age of four.
The Scottish government is considering setting up a foresnsic secure inpatient facility in Ayrshire and Arran.
Mental health minister Maureen Watt said: “We will now work closely with NHS National Services Scotland on developing the proposal further.”