There were serious failings in the care given in prison to a vulnerable woman who died after fellow inmates bullied her and goaded her to take her own life, an inquest jury has found.

Jessica Whitchurch, 31, who was described by her family as caring and fun, was discovered unconscious at Eastwood Park prison in Gloucestershire with ligatures around her neck. She died in hospital two days later.

She was under observation by staff at the time, having apparently placed other ligatures around her neck less than two hours before.

At the end of her inquest in Flax Bourton near Bristol, jurors said her vulnerability was exacerbated by bullying from other inmates. The panel said that Whitchurch, from Nailsea in Somerset, was goaded by other inmates but officers had not stepped in to challenge them.

The jurors highlighted failures in communication between prison officers and health staff and said the observation she was placed under was insufficient.

Speaking afterwards, Whitchurch’s sister, Emma Gardiner, said: “The jury has finally confirmed what we have known all along, that Jess’s care in the hours before her death was inadequate and that her death was avoidable.”

Whitchurch had been jailed for a street robbery and was nearing the end of her sentence. She was from a close-knit family who said she loved life but had mental-health problems addiction issues and had repeatedly self-harmed and tried to take her own life.

The inquest was told that Whitchurch was bullied in prison and on 18 May 2016, at around 12.19pm, she was found in a state of distress with ligatures around her neck in her cell.

Prison staff put her on twice-hourly observations but prisoners were heard goading her into killing herself.

At 1.28pm, Whitchurch was found unconscious with ligatures around her neck. Her heart had stopped.

In its conclusion, the jury said it could not decide if the incident was suicide or an accident. “In our view it remains equally plausible that her death was unintentional, resulting from an extreme self-harm episode,” the jury said.

It added: “Jessica’s presentation exhibited borderline personality disorder and a tendency towards repeated self-harming. Her inherent vulnerability was exacerbated by frequent bullying by other inmates.”

The jury said the observational regime was “deeply inadequate and contributed to Jessica’s death”. It continued: “The jury believes that this ligature episode was compounded by bullying and goading at the time by nearby inmates, which went unchallenged. In summary, Jessica’s care was inadequate as a result of organisational failings in prison service staffing.”

Selen Cavcav, a caseworker at the charity Inquest, which supported her family, said: “A jury member at this inquest asked the pertinent question: ‘Given her presentation, should Jessica have been incarcerated in prison at all?’ This critical conclusion clearly answers that. This country criminalises women for their own suffering, imprisoning them in places that cannot possibly end the cycle of harm or keep them safe.”

According to the Howard League for Penal Reform, in 2016 there were 22 deaths in women’s prisons, the highest number on record.

A Prison Service spokesperson said: “Our thoughts and sincere apologies remain with Jessica Whitchurch’s family and friends, and we are determined to learn every possible lesson from her tragic death.

“We have made rapid improvements at Eastwood, including better support for women both in their first days and as they progress through their sentence.”