When a customer of the shop asked about 15 gold rings advertised online, the manager's suspicions were aroused and a stocktake found the same items were missing.
A police search of Vlaanderen's home turned up the gold rings - plus four silver rings and two bracelets.
The stolen jewellery was worth $6000 (NZ$6436).
Magistrate Haydn Stjernqvist told the defendant her offending was "very serious" and that she was "already halfway across the Tasman".
Vlaanderen was sentenced, in the Maroochydore Magistrates Court, to 15 months' probation; no conviction was recorded.
The teenager, who quit Pandora and now works as a cafe waitress and barista, suffered from "depression issues", her lawyer said. She stole because she was struggling to pay her bills.