The man who killed Karen Allen's younger brother is serving four years for manslaughter and could be free after less than two years in jail.
Victims' families want the punishment to fit the crime
John Burke, 40, died this year after a single headbutt from labourer Paul Cunningham outside a Blackpool pub.
He survived the initial attack but was found dead days later at his home.
Calls from the government's legal advisers to reclassify murder in degrees and limit manslaughter cases have been met with strong reaction.
Some victims' families and support groups have voiced concerns that change could result in shorter sentences
But Ms Allen welcomes a review for the opposite reason - believing it may bring "fairer" sentencing.
Her brother died after an attack in April by a stranger, in which he fell and hit his head on the pavement.
Cunningham had a violent past, the court had heard, and had previously been convicted for wounding and actual bodily harm.
"We accept as a family he didn't mean to do it but if you go out, use violence and you cause somebody's death, I don't see how anybody could think that two years served is enough for killing somebody," Ms Allen said.
She, her parents and family were expecting a longer sentence, she said, but were told that was an average sentence, taking into account the circumstances and Cunningham's guilty plea.
"We were really shocked and very upset by how little time he had to do," she said, as were the police and Crown Prosecution Service.
Her 16-year-old nephew, Daniel, is finding it hard to come to terms with the sentence as he faces his first Christmas without his father.
"He came on Saturday and was going on about it then," she said. "My mum was saying 'you have got to let it go, because it won't do you any good'."
She hopes a review and changes could bring fairer sentencing in practice.
"Now, it's murder or manslaughter. But I do believe there are all sorts of reasons for killing somebody from euthanasia or mercy killing to sustained violent attack, so to only have two things is such a narrow category.
"He might not have gone out with the intention of killing my brother, but we all know that if you do certain things you could kill somebody.
"Hopefully if it does change, there won't be people like us who feel so let down by the law."
Criminal lawyer Julian Young also hopes the changes may mean punishments are more likely to fit the crime.
A sentencing judge, he points out, has only three options open in a murder case - life imprisonment, 30 years or 15 years - and has to work within those limits.
"Murder really should mean intending to kill someone, with a life sentence automatically and a tariff attached to that," he told BBC News 24.
"The other convictions - for murder two or three or manslaughter, or culpable homicide - gives the judge a far wider discretion to impose an appropriate sentence, to make the punishment fit the crime.
"This is in no way saying that any homicide is anything other than exceptionally serious, the most serious type of offence the law can imagine."
But he stressed the judge should pass a sentence that gives even the killer some hope for future rehabilitation - unless it is a really terrible killing.
Morley killing highlighted
John Merzetti's friend David Morley was murdered on London's South Bank in October 2004. Last week four people were convicted of manslaughter, but cleared of murder.
He said the jury had had no other choice in the case and he thought there could have been a more serious conviction if degrees of murder had applied under the law in England and Wales.
"Something has to be changed. Sentences have got to be more meaningful," he said.
The Morley case was highlighted by Commander Dave Johnson, head of the Metropolitan Police's Homicide Unit.
He welcomed the review because "the landscape's changed during the past 30-40 years since the end of the death penalty".
"It can't be right that juries have to make a decision whether or not to sentence somebody to being guilty of murder when they may be frightened of sending a young person to jail for the rest of their life."
And, he said, the complexity of murder had developed over the years with diminished responsibility, provocation and mercy killing.