First she would need to have a very solid strength base. The type of base established through periodized strength training, not dance training. This strength base will diminish the chance of injury which increases with plyometric training, especially if there is no solid base.
After this base is established she would start with different plyo exercises that closely mimic her dance jumps, including proper landing technique. This should be done with both legs and progress into unilateral training. Plyos are generally only done 1-2 times per week and no more due to the heavy impact.
Options include box jumps, squat jumps, dead jumps, split jumps, box drops, and post activation potentiation.