Jerram is in reflective mood as we lunch in her light-filled office at the Glebe Coroner's Court over sandwiches, Portuguese tarts and mineral water. Bringing sandwiches over was her suggestion. After fitful negotiations over a restaurant, she had confessed she was not much of a ''luncher'', though she does enjoy a good, roistering weekend dinner. She steps down from the coroner's post on the first of next month, just days before her 68th birthday. It has been 6½ years in a job that might have left someone more vulnerable with permanent nightmares. Yet she has loved it. ''Fabulous work,'' she says, ''the most interesting in the whole of the law that I've yet done - you play detective, medico, lawyer all at once. And unlike … judges and magistrates, we get the whole brief, in fact we order the brief.'' The coroner also gets to ''resolve things'', she adds. ''A friend said to me once, 'you always want to try and understand why everything happens.' And you can't always understand why everything happens, but here … you mostly can.'' Yet for all the satisfaction she has derived from mystery-solving and giving bereaved families explanations (not ''closure'' - a word she hates), there are some cases Jerram can never quite move on from. ''Children - anything with children.'' There was the small girl savaged by a neighbour's dogs which broke free of their chains after she had wandered up the street to visit them. 'I remember going down to the mortuary to see her; it was like a little doll with no face. It was just appalling, and that haunted me for days, as the Balmain young ones did … I didn't have to go but I was going to have to do the inquest and just thought I'd better.''

Then there was the young teen, only son of Chinese parents, who died from anaphylactic shock after eating a walnut biscuit offered to him by another student at school. ''The mother looked as if she was just dying of grief, her hair was coming out, and the father saying, 'I don't want to live. I don't want to live … its my fault.' It wasn't, of course. The little boy didn't have his EpiPen with him. The daughter read a little thing [in court] and said, 'We used to be so happy and now I just hear my mother crying through the wall,' and I thought, 'Oh God, it doesn't help them if I start crying.' But I did. And I looked around the room and here were all these lawyers crying.'' Then there were the Lin family murders, two young boys and their parents, savagely bludgeoned in a home in North Epping in 2009. ''There was an awful aura hanging over that house,'' she says. Fabulous work ... you play detective, medico, lawyer all at once. But if there is grief in the courtroom, there is also often humour, some of it dark-tinged, behind the scenes. ''The pathologists are appalling, you should hear their black jokes,'' she says, breaking into her own throaty and infectious laugh. ''The job hasn't toughened me up to actual death. But I do think that laughing helps.''

Unlikely as it seems, she says the court - despite the proximity of the adjoining morgue - is ''a sort of happy place to work. I know that sounds appalling but people actually work together, we have a really good team.'' Her departure from the State Coroner's post will not mean a complete exit from the bench. She hopes to continue locum work next year at the request of the Chief Magistrate. There is a strong echo here of her first attempt to retire in 2001, when she resigned as NSW Deputy Chief Magistrate to return to New Zealand with her second husband, Philip Taylor, known to friends as ''Squizzy''. They bought a farm outside Christchurch, had horses, doves, chooks and a garden; but she kept returning to Sydney several times a year to fill in on the bench as acting magistrate. In 2007 then attorney-general John Hatzistergos asked her to pick up the State Coroner's role. She leapt at it. ''I was too young to have stopped,'' she says.

She and ''Squizz'' have a smaller farm now, a weekender near Oberon, where she does a ''lot of calm thinking - and decent physical exercise without going to the gym because I hate going to the gym''. She calls it her ''sanity preserver''. New Zealand-born Jerram trained as a teacher, arriving in Australia with her first husband and two small children in 1969. She studied law part-time and worked as an industrial officer for the Independent Teachers Union before joining Legal Aid, and ultimately the magistrate's bench. She ''loved'' Legal Aid, she says. ''The criminal law is so interesting.'' Accumulating that ''bit of experience of humans and life'' has proved invaluable as a coroner, she believes, as has ''being a bit older … [and] having some empathy, but knowing how to draw a line''. And it has been an advantage not to be squeamish. While some of her deputies avoid visiting the morgue, Jerram will occasionally when she is puzzling over something. ''The last time I went down there was after that helicopter crashed down at Bulli Pass [in March] with four scientists on board,'' she says. ''Word had come back that they were unidentifiable and I just wanted to see whether that was so. Well, boy, was it ever - you could hardly tell that they were human bodies. Poor things.''

Her own family are no strangers to sudden bereavement. Her niece Jane Jerram, a ''splendiferous girl'', died on Mont Blanc in France six years ago, aged just 26, after a summer storm caught her and three friends 800 metres from the summit. ''For the first few months my brother and his wife were looking for someone to blame,'' Jerram says. ''And I don't know that that was the answer … I think I learnt that in grief even highly intelligent, educated people can become, if you like, un-sensible.'' The family is ''much better now … but they are just sad''. Each year between 6000 and 7000 unexpected, accidental or suspicious deaths are reported to her office, of which around 250 give rise to inquests. Another task is to approve urgent requests for the removal of organs for transplants, which can, she says, lead to some ''gruesome conversations over dinner parties on Saturday night''. Jerram's first ''big production'' was the case of Private Jake Kovko, who died of a gunshot wound to his head in his army digs in Iraq. ''[The mother] was utterly convinced that her boy had been murdered, and I'm utterly convinced he wasn't - he was fooling around,'' she says. Recent cuts by the O'Farrell government to the judiciary will mean the loss of one of the deputy coroner's posts, which worries her because of probable delays and a heavier load for those who remain. ''People are not going to stop dying and the population is growing, so our workload can only increase.''

Jerram has never shied away from criticising systemic failures. She has lambasted the Department of Immigration and security firm Serco over deaths at Villawood detention centre, and the ambulance service over a murder-suicide committed by a mentally ill paramedic; recommended radical changes to the boarding house industry; and torn strips off the police in the recent case of Roberto Laudisio Curti, the Brazilian student who died after being tasered multiple times by a group of officers in the Sydney central business district. When she handed down her findings in the Curti case, recommending disciplinary charges against some of the police involved, Jerram likened their ''ungoverned pack mentality'' to the ''schoolboys in Lord of the Flies. Loading ''Some of their behaviour was shameful,'' she says. ''I think it's very much part of this job, to be able to be independent and speak out. Otherwise, what are we here for?'' After a post-sandwich cup of tea, Jerram asks if I would like to see the morgue. It is a confronting, yet oddly intriguing, invitation. But I am running late. We pack the sandwich plates into a bag. They clink loudly as I head out past the front office. ''Careful,'' Jerram calls out with a laugh. ''They might think they are bottles.''