Smith's lawyer Annabel Maxwell-Scott said her client was 23 weeks pregnant with her third child at the moment and the father of the child had recently gone missing.
Ms Maxwell-Scott said it was the defendant's circumstances that made her susceptible to her brother's alleged plan.
"Her vulnerability made this all too easy," she said.
Phillip Smith allegedly fled to South America while on temporary release from Spring Hill Corrections Facility in South Auckland on November 6, using a passport his sister helped him obtain.
He was serving a life term at the time for the 1995 stabbing murder of the father of a boy he had sexually abused.
At the time, Smith - who had tracked the family down to a Wellington house where they had moved to escape him - was on bail for the sexual offending and charges of blackmail against a man who later killed himself.
He was detained in Rio de Janeiro on November 13 - a week after he left New Zealand last year.
Smith appeared in Auckland District Court at the end of last year where he argued "excessive" media coverage meant that he would not get a fair trial.
He provided an affidavit to the court and even got into the witness box to express his distaste for one media report which contained the word "escaped" nine times.
Not once was it prefaced by the word "alleged", Smith said.
He also took umbrage at a government report which he claimed made similar assertions.
Police Commissioner Mike Bush has been called to give evidence but is in the process of challenging that ruling.
Joanne Smith will serve her home detention sentence at a Palmerston North address.
