Her portrayal of Joan "The Freak" Ferguson had made her a household name in Australian fans, with scores of fans including the Melbourne teenager.
In 1984, the girl was a patient at a psychiatric hospital where she befriended a woman who also worked on the show.
That woman arranged a meeting with Kirkpatrick, after which the actress collected the fan from the hospital and took her to Prahran.
She cooked dinner for the girl and they watched some television, before going to Kirkpatrick's bedroom where the actress sexually abused the 14-year-old.
Kirkpatrick gave the girl a yellow jumper, signed a photograph and drove her back to hospital, the court heard.
She would have known the girl was especially vulnerable, Mr Mealy said.
"The defendant showed no remorse, instead simply protesting at a distance, in her terms, the untrue and malicious allegations," Mr Mealy told the Melbourne Magistrates Court.
"The vulnerable in our society need to be protected."
Kirkpatrick was found guilty on Thursday of two counts of indecent assault and one charge of committing a gross act with a person under 16.
When the allegations were aired last month, Kirkpatrick vowed to fight them.
She told police they made her feel ill and were malicious and untrue.
But Mr Mealy ruled the victim's testimony was truthful.
Kirkpatrick must perform 100 hours of community work in Victoria as part of her punishment, and has been placed on the sex offenders register for eight years.
She has been ordered to give police a DNA sample and take part in rehabilitation programs.
A pre-appeal mention of her matter is listed in the County Court of Victoria on September 11.
Kirkpatrick shot to fame for her role in Prisoner and has since appeared in television shows All Saints, Pizza, Blue Heelers and Water Rats.
She most recently had a role in the theatre musical, Wicked.
- AAP
