A mother who leapt to her death in Dartmoor with her five-year-old son after killing her younger son at home feared social workers would take her children away from her.
Katherine Hooper's family was being monitored and Sam, two, and Josh, five, had once been in temporary care.
And the 24-year-old had also overdosed after leaving the boys' dad Neil Patterson, 54 - who is on trial next month, accused of attacking her.
Police have confirmed that social workers and other agencies were meant to be safeguarding the family and that a serious case review would now examine whether they had failed.
Katherine jumped 100ft to her death from rocks at a Devon beauty spot on Friday with her five-year-old son Josh Patterson on her shoulders.
The body of her youngest son, Samuel, two, was found at their home in Paignton. It is believed he had been suffocated.
It emerged that Katherine's estranged partner Neil Patterson appeared in court in April accused of assaulting her. He pleaded not guilty and is due back in court next month.
The incident is alleged to have taken place on April 28, the day before she went missing overnight for around 10 hours. Katherine was said to be suffering from depression after the incident.
Her friend Danielle Holland revealed how Katherine - who had a safety alarm and panic button in her house - came close to killing herself in April.
She revealed: "She overdosed, ran into some fields and was there for 24 hours. She had hypothermia and spent days in hospital."
But there were other problems. Danielle Holland said Katherine - thought to have lost her hotel chambermaid's job - was so broke she offered her cat to a neighbour as she could not afford to keep it.
She said: "Kat found it hard. But she was a special mum and her kids were amazing. I saw her a week ago and she looked fine. She didn't say she needed anything. She loved her kids to bits and seemed happy."
Neighbour Janette Nolan, 53, told The Sun: "Social services are partly to blame. She told me it was like they were waiting for her to slip up so they could take the kids.
"They were on her back about petty things when they should have been protecting her.
"She was lovely, innocent, caring and kind but seemed vulnerable and lost. I think she was frightened of her future as a single mum, but you'd never guess she'd do this. They were lovely boys."
A postmortem is being carried out into the cause of Katherine's death.