"She was just happy to get some of it back," Nicky Hilton, 26, told PEOPLE Saturday while hosting a Halloween party at Las Vegas's Pure Nightclub.
Paris Hilton, 28, was a victim in a string of celebrity burglaries that also included Rachel Bilson, Megan Fox, Ashley Tisdale, Lindsay Lohan, Orlando Bloom and Audrina Patridge. Last week, a group of mostly teenage suspects was arrested in a sting operation, and police say more arrests are expected.
Nicky Hilton remains in disbelief that such a crime even took place. Her sister, she says, "lives in a gated community with supposed state of the art security."
Rick Hilton, Nicky and Paris's father, said he didn't know all the details about the burglary, but said of the outcome that his daughter is "happy about it."