A good samaritan from Northampton who once gave first aid to a murder victim died in her sleep after taking methadone, a coroner ruled.
Kellie Marie Harrison, 30, from Northampton, died at her partner's flat in October 24 last year.
Her partner woke up from a nap they had taken together to find her lying dead next to him.
Kellie's mother, Sarah Noble, said: "I still have many questions about the death of my daughter. She had her whole life ahead of her."
She had been staying at her partner's flat on the afternoon of October 24, 2016, when he came into the kitchen to find she had consumed over half-a-bottle of his methadone with alcohol.
She vomited shortly after, and the couple chose to take a nap.
When her partner woke up around five hours later, he found Kellie was not breathing.
A paramedic was called to the house but declared Kellie had been dead for some time.
A post-mortem found methadone, diazepam and a trace amount of cocaine in her bloodstream.
HM Coroner Anne Pember said: "This was an accidental death and there is no evidence that Kellie had wanted to take her own life."
In January 2015, Kellie, while walking her son to a martial arts class, discovered 35-year-old Jon Casey, who had been fatally injured in an attack by the railings in Barrack Road, Northampton.
She called an ambulance and tried to revive Mr Casey, and even used her son's scarf to stop the bleeding.
Mr Casey later died of his injuries and a murder inquiry was launched.
Kellie's mother Sarah Noble, in a statement read out by the coroner, said: "In 2005, while living in a block of flats in Northampton, she discovered a fire and was able to raise the alarm. She alerted everybody else in the building, essentially saving their lives.
"Her little boy was the apple of her eye. She dressed him smartly and he gave her a lease on life. She would have done anything for him."