Nicole Vaisey was denied bail at a preliminary hearing at Fowler Town Court in upstate New York.
She and her boyfriend, Stephen Howells II, are accused kidnapping two sisters from their family's produce stand last week.
A detective testified Vaisey referred to the kidnapping as a "shopping trip" and the couple wanted the girls, ages seven and 12, to be their slaves.
"They had been thinking about this for at least a week, but more than that so it was very calculated, very planned and these are sexual predators," Prosecutor Mary Rain said.
"This is a very unusual circumstance where somebody potentially charged with a very serious crime, about as serious as it gets - drives themselves to an investigatory agency and then talks to the investigators. That's bizarre in this business," Defense Attorney Brad Riendeau said.
The girls were found alive after detectives say the couple, frightened by news reports of the kidnapping, dropped them off in an isolated area.
The couple is facing a lesser charge of 2nd degree kidnapping so the victims will not have to testify.
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