A doctor convicted of manslaughter by gross negligence over the death of a six-year-old boy in her care has won her bid to be reinstated to the medical register.

Dr Hadiza Bawa-Garba, a junior doctor specialising in paediatrics, was held responsible for the death of Jack Adcock, who suffered heart failure after going into septic shock while in her care at Leicester Royal infirmary in 2011.

She was removed from the medical register in January, after the General Medical Council (GMC) appealed against a decision that she be suspended for a year. But three appeal court judges ruled on Monday that the divisional court had been wrong to interfere with the earlier decision.

In a statement read out to the court, Sir Terence Etherton, the master of the rolls, said: “The [medical practitioners tribunal service] was an expert body entitled to reach [its] conclusions, including the important factor weighing in favour of Dr Bawa-Garba that she is a competent and useful doctor, who represents no material continuing danger to the public and can provide considerable useful future service to society.

“The members of the court express their deep sympathy with Jack’s parents, who attended the hearing in person, as well as respect for the dignified and resolute way in which they have coped with a terrible loss in traumatic circumstances.”

Bawa-Garba welcomed the appeal court’s decision. “I’m very pleased with the outcome, but I want to pay tribute and remember Jack Adcock, a wonderful little boy that started the story,” she told BBC’s Panorama. “I want to let the parents know that I’m sorry for my role in what has happened to Jack.

“I also want to acknowledge and give gratitude to people around the world, from the public to the medical community, who have supported me. I’m very overwhelmed by the generosity and I’m really grateful for that.”

Jack’s mother, Nicky Adcock, said the verdict was an “absolute disgrace” that set “a precedent for doctors to do exactly what they like.” She pledged to fight the decision at the supreme court.

“All they’re concerned about is the doctors in the profession,” she told Sky News. “It seems people seem to be quite scared of the doctors, they seem to think they’re untouchable.”

Bawa-Garba had been on her first shift back after 14 months away on maternity leave on 18 February 2011, when Jack, a young boy with Down’s syndrome, was admitted to hospital with sickness and diarrhoea. After an initial examination, he was treated for acute gastroenteritis and dehydration but his condition continued to deteriorate.

It subsequently emerged that he had been suffering from pneumonia, and antibiotics were given. But he went into septic shock, which led to organ failure and a heart attack, and he was pronounced dead at 9.20pm.

The case has caused a storm within the profession. Bawa-Garba was found guilty in 2015 of gross negligence manslaughter and received a 24-month suspended sentence. The medical practitioners tribunal initially decided she should be allowed to continue her training and practise again as a doctor after a one-year suspension.

Supporters of Dr Hadiza Bawa-Garba outside the court, including Dr Ramesh Mehta (far right) from the British Association of Physicians of Indian Origin. Photograph: Yui Mok/PA

But the doctors’ regulatory body, the GMC, appealed against the decision, saying she should be struck off the medical register. The high court ruled in the GMC’s favour in January.

Etherton said the case was unusual. “No concerns have ever been raised about the clinical competence of Dr Bawa-Garba, other than in relation to Jack’s death, even though she continued to be employed at the hospital until her conviction. The evidence before the tribunal was that she was in the top third of her specialist trainee cohort.”

The case had attracted particular attention from doctors, many of whom accused the GMC of acting heavy-handedly. Supporters pointed out that Bawa-Garba had just returned from an extended leave of absence; that three medical colleagues were absent for much of her shift; she had had no break; there was an IT system failure at a crucial time; and that she had to deal with other seriously ill children.

More than £160,000 was raised to help Bawa-Garba appeal against the decision, while more than 1,500 doctors signed a letter expressing “deep-seated concerns” at her treatment and arguing it threatened the “culture of openness” that was critical to learning from medical error and would result in others not being honest in their own self-appraisals.

We believe that if [Bawa-Garba] was white she would not have landed in this spot – we are very clear about it Dr Ramesh Mehta

There were muted celebrations among doctors after Bawa-Garba’s reinstatement. One who attended the hearing at the Royal Courts of Justice in London and asked not to be named said she had been ready to resign if Bawa-Garba had not been reinstated. Another, Richard Nicholl, a paediatrician working at Northwick Park hospital in north-west London, said he was pleased with the result. “It doesn’t change the fact that a child died, but this was always about trying to examine safety in the NHS, not trying to protect one individual,” he said.

Dr Ramesh Mehta, the president of the British Association of Physicians of Indian Origin, who was also in court, said the case of Bawa-Garba, who is from Nigeria, had exposed issues of diversity within medical malpractice claims.

“We believe that if [Bawa-Garba] was white she would not have landed in this spot – we are very clear about it,” Mehta said. “There are so many other cases where this has happened and other people got nothing, while black and minority ethnic doctors get punished.”

Dr Samantha Batt-Rawden, the chair of the Doctors’ Association UK, said: “This is a small step in the right direction for patients and doctors. We need to make sure that patients and families get the answers they need through open and transparent engagement with NHS organisations. The GMC needs to rethink its priorities in enabling this to happen rather than aggressively pursuing doctors in the courts.”

Dr Rob Hendry, the medical director at the Medical Protection Society, said after the ruling: “We are very pleased the appeal submitted by Dr Bawa-Garba’s legal team has been successful. The MPS supported Dr Bawa-Garba for seven years. We know how much this will mean to her, and to the profession.

“The strength of feeling on this case amongst our members and the wider healthcare community has been unprecedented. It is vital that lessons are now learned to avoid other doctors having to go through the same ordeal.”

The president of the Royal College of Physicians, Prof Jane Dacre, said the judgment was “a welcome step towards the development of a just culture in healthcare, as opposed to a blame culture.

“But our thoughts today are first and foremost with the family of six-year-old Jack Adcock, who died as a result of the errors that were made. While we understand the judgment is not what they hoped for, the RCP believes it will help us develop a culture in which families like them will be more likely to receive the support, clear explanations and apologies they need and deserve.

“We hope today’s judgment will provide some reassurance to doctors, particularly our trainees, that they will be protected if they make a mistake. We remain concerned at the impact this case has had on professional reflection, which is crucial to helping us improve our performance.”