"Any sexual offending is serious let alone that against an innocent child," she said. "But of course you know that because you were a child once upon a time and you were sexually offended against, and I have no doubt that is why you are here today."
Judge Sharp said she needed to consider what sentence Justice Joseph Williams would have made, had he known of the offending when he jailed Gillies in 2010.
"You were a friend of the victim's mother and you had been invited into their home," Judge Sharp said.
"There are no mitigating factors relating to the offending."
If Gillies was ever released from prison "the community needs to be safe from you", she added, and this would only be so if Gillies took all rehabilitation measures while incarcerated.
Judge Sharp said Gillies had a "substantial and very significant" list of offending, most of which was of a sexual nature.
"These go back as far as 1988," she said.
Gillies' sexual offending dates back to two rapes in the late 1980s, with several violent offences, mainly against women, in the years since.
In September 2010, Gillies was jailed for 12 and a half years for repeatedly raping a woman and trying to blackmail her with a $5000 cash bribe.
He was convicted of nine charges, including four of rape, two of unlawful sexual connection and one each of blackmail, male assaults female, and injuring with intent.
During his 2010 High Court sentencing he was also given a minimum non-parole sentence of six years.