Regina Kaye Arthurell has "unequivocally demonstrated a proclivity violently to terminate the lives of fellow human beings", Justice Richard Button said in the NSW Supreme Court on Thursday.

To have committed homicide on two separate occasions was exceptionally rare, but to have been "convicted of committing it three times, including once whilst on parole for a previous homicide, I dare say is approaching the unique".

He ordered the unwell 75-year-old, who was released on parole in November, to be subject to an extended supervision order for two years, rather than the three years sought by the State of NSW.

He imposed more than 40 conditions, including requiring her to be subject to electronic monitoring despite her lawyers contending it was unnecessary and oppressive.

She has to notify her supervisor of any significant change in her appearance, including the acquisition of any new wig, and to be photographed after any such change.

Arthurell first killed in 1974, having committed the manslaughter of her stepfather Thomas Thornton who was said to have been very abusive.

In 1981, she committed the manslaughter of naval officer Ross Browning in a Northern Territory robbery.

In 1995 she murdered her former partner, Venet Mulhall, by bludgeoning her to death with a piece of wood at her Coonabarabran home in central NSW,

Alcohol was implicated in all of the killings, which were committed under her birth name Reginald Kenneth Arthurell before she came out as transgender in custody.

The judge said he had read the victim impact statement of Ms Mulhall's brother, who has raised fears she will kill again.

Arthurell is now blind in one eye and her other health problems include significant hand tremors.

While there had been inevitable "bumps in the road", the judge said Arthurell had not breached any of her parole conditions since being released in November.

"Furthermore, the uncontradicted evidence is that the defendant has maintained her very longstanding abstinence from alcohol."

She now lives in crisis accommodation, after being forced to leave an aged care facility when her background became known, which also led to her no longer being welcome at her GP's.

Her membership of an online transgender support group had ended sourly although the reason was not clear, the judge said.

"In summary then, it is clear that the defendant is leading an extremely circumscribed, isolated, difficult life in the community."

The judge accepted that she is making a sincere effort at rehabilitation in very challenging circumstances.

But these factors had to be weighed against the simple fact that she had committed unlawful homicide thrice, over a period of many years and in notably different contexts.

A frail, even physically disabled, person could inflict fatal harm once armed with a weapon.

In ruling the supervision order was appropriate, he said in light of the established pattern of inflicting fatal harm, beginning almost 50 years ago, "for her to be completely at liberty in the community would simply be far too dangerous".

Ordering her to be subject to electronic monitoring, the judge said the fatal offending occurred in locations hundreds, sometimes thousands, of kilometres apart.

Even very frail and elderly people can use public transport to travel long distances in short times before their absence is detected.

And in imposing a drug and alcohol rehabilitation condition, the judge said alcohol was available in every suburb of Sydney, even in lockdown.

"The defendant, as I have said, is leading a very difficult, lonely life.

"It is not unrealistic to think that she might begin to seek solace in alcohol, with potentially disastrous consequences."

Australian Associated Press