Kim Leanne Snibson, 37, has pleaded guilty to kidnapping and murdering Nowra Hill horse stud owners Gregory Hosa, 56, and his wife Kathryn McKay, 44, in January 2006.

The couple's remains were found burning in two metal 44-gallon drums in the Tomerong State Forest, south of Nowra.

Snibson spent two days in the witness box last week at her sentencing hearing, which continued yesterday in the NSW Supreme Court before Justice Terence Buddin.

Crown prosecutor Paul Leask told the judge Snibson had "attempted to weave a false account around objective and provable facts".

"The result is a farcical and shameless invention that denies any responsibility, moral or otherwise, in the kidnapping and murder of Greg Hosa and Kathryn McKay," he said.

"Where she could not contrive an account capable of such calculated factual cohesion, the offender employed the device of implicitly blackening the character of witnesses and the deceased."

In her evidence, Snibson blamed co-offender Stacey Lea-Caton for the murders - in stark contrast to his evidence - and claimed to have been scared of him.

She denied manipulating him and another man, Andrew Wayne Flentjar, by making up accusations the victims had molested a child and also filmed her engaged in sex acts.

She also said she had an affair with Mr Hosa.

Lea-Caton is serving a maximum of 22 years in jail after admitting to the kidnappings and murders, while Flentjar received a maximum of seven years for kidnapping.

Snibson's barrister Alex Radojev said it was unlikely the judge would accept anything Lea-Caton said unless it was independently corroborated.

Unlike Snibson, Lea-Caton had a history of violence, and had told numerous lies about his involvement in the January 2006 events, Mr Radojev said.

Justice Buddin noted the great difficulty in making findings about the killings themselves, referring to the co-offenders as "unreliable historians".

Mr Leask said it may properly be found Snibson's motive for the kidnapping was "entirely out of self-interest and for personal gain".

Sentencing submissions will continue tomorrow.