Suzanne White, a partner at Leigh Day solicitors, said Irene “should have been listened to and kept safe”.
She said: “The finding of neglect, which represents a gross failure in Irene’s care, is shocking and appalling for the family to hear.
“The inquest has brought into sharp focus a series of serious failings in Irene’s care which should never have happened.”
She added: “Too many people living with sickle cell disease, predominantly from black communities, report feeling dismissed, disbelieved, and marginalised when they seek care.
“This must change. Listening to patients, acting promptly on clinical warning signs, and ensuring staff have the right training and support are not optional, but basic standards of care.”
A spokesperson for Frimley Health NHS Foundation Trust said: “We would like to express our deepest condolences to Irene Arthur’s family and friends. We are truly sorry for the shortcomings in the care we provided and fully accept the coroner’s findings.
“We are committed to learning from this case and have taken steps to address the issues raised ensuring lasting improvements for our patients and their families.”