Melissa Jack, 20, had suggested that student Matthew Williamson had forced her into the fling and claimed that he had filmed the incident and tried blackmailed her.
She made the remarks to police after going to them in a bid to obtain footage of their sexual encounter that she said Mr Williamson was planning to upload to Facebook.
She had claimed earlier: "I wanted to tell them that I was being threatened and blackmailed."
It led to her former sexual partner being cautioned and detained and interviewed over the allegation before Jack admitted that she had lied.
When Jack, of Aberdeen, appeared for sentence at the city's sheriff court yesterday, Sheriff Graeme Napier said that false allegations or rape could not be condoned.
But he said he had sympathy for Jack, who clearly did not respond to her situation in an appropriate way.
Admonishing her, he added: "It is difficult for me to see where the public interest is in having prosecuted this young woman."
Mr Williamson was not arrested and was released so officers could make further inquiries.