Jodie Simpson, 38, fell into a vegetative state after taking an overdose of drugs at her home in Barrow, Cumbria, in 2012.
She died in June after her family fought for a legal ruling to withhold nutrition and hydration.
The coroner ruled she died of a brain injury resulting from the overdose.
Ms Simpson's brother Michael Devlin told the inquest his sister had a history of drink and drug use and had been on a "weekend bender" before he found her collapsed at her home.
She ended up in a vegetative state with no sign of consciousness.
She was able to breathe without assistance but needed to be fed and given liquid through a stomach tube.
Her mother Jean Simpson said: "I knew from the beginning there was no hope, my worst fear was that she was actually minimally unconscious.
"No one would want to live like that."
Doctors agreed there was no chance of recovery yet the legal application to allow her to die was subjected to years of delay.
She told the inquest her family was "treated as insignificant" by the authorities and she had lost faith in professionals.
Cumbria Care Commissioning Group has since apologised for the process taking so long.
The coroner said looking back to the events of 2012, there was no evidence Jodie Simpson intended to take her own life.

The company has been in dispute for more than a year with the RMT over changes to guards' roles on trains.
RMT conductors saw the changes as a ploy to phase out a second person on trains. It has now proposed a six-month trial with two staff guaranteed on all affected services.
But Southern said what the RMT wanted was "a guarantee to cancel trains".
Under the changes to guards' roles, which were also opposed by the Aslef train drivers' union, responsibility for opening and closing doors passes to the driver rather than the conductor.
The practice is called driver-only-operation (DOO).
Southern rail strike: What's it about?
RMT leaders have set out an "accessibility guarantee" plan, which would ensure a driver and an on-board supervisor staff all trains.
This would mean disabled, elderly and vulnerable passengers would be provided with guaranteed assistance from on-board staff on all services without the need to book in advance, the union said.
RMT general secretary Mick Cash said: "We are hoping the company will reconsider our proposal for a trial six-month period of an accessibility guarantee.
"We would hope that they would agree to this sensible proposal as the Association of Train Operating Companies consultant's report has said train companies should guarantee a second person to comply with their legal obligations."
But a spokesman for Southern said: "The guarantee the RMT wants is a guarantee to cancel trains. We want to put the passenger first and keep trains running.
"Driver-controlled operation is safe and provision for those who need assistance has not deteriorated while, at the same time, service levels have steadily improved."
RMT members on Southern will stage a fresh strike next Monday, while Aslef has banned overtime.
A woman who spent four years trying to get permission to allow her daughter to die has told an inquest the delay was "excruciating".
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Union leaders have held talks with MPs over a plan they claim could end the long-running row on Southern rail.