This is one that you should probably think through a bit. "Advanced" is quite a relative term and she may be better off on an all around ski, a "slalom cut" perhaps.
My son is a J-4 racer and for his age (12), he pretty advanced. At 93 pounds, he is on a 138 slalom; his GS will be 149's.
At 20, her muscular development and the ability to generate power and bend the ski will matter here. Our rep indicates that regarding the Stockli skis that my son has, the weights are in the acceptable range but are close to the limits. Check with the Dynastar folks to make sure she will not overwhelm a kids ski.
Many of the kids skis are more "race motif" than actual race skis. Check the local library for the first editions of Ski or Skiing Magazine, they had a whole section that detailed most of the kids line and that may give you some insight. They did a pretty nice job on the race skis.