SnowWonder - You describe your daughter's current skis as "Dynastar Junior Slalom race skis", yet, when I Google this phrase, all I come up with a page on Ski Magazine's website describing the Dynastar Team Omeglass 64, and it is categorized under "Junior Skis: All Mountain Expert", not as a race ski ( http://www.skimag.com/skimag/gear/ar...335274,00.html
) . Is this the ski she is currently on?
Does your daughter race (ie, in organized events) or not? If not, I would not recommend any race ski to her.
You said that you are looking for a "more GS ski". There is a huge difference between true race skis designed for the GS specialty, and more general purpose skis designed with a less radical sidecut (shape) so that they are not so "twitchy" at speed. My guess is that you are looking for the latter. It also sounds like you would like to have good rough / ungroomed snow performance from this ski. If so, you should consider putting her on a ski which is a bit wider underfoot than her current ski.
If your daughter is indeed on the Dynastar Team Omeglass 64, with a 107/64/90 profile at 140 cm length, it has ( http://www.websurd.com/epic2004/PMSidecutRadCalc.xls
) a sidecut radius of around 11 meters. This is very tight for large radius turns, especially through rough / ungroomed snow. You probably want to put her on a ski with a radius in the 15-18 meter range.
Last season, my daughter was in the same situation as yours, ie, was on a pr of 140 cm junior skis that while reasonably stiff for junior skis, were soft enough that I could see the tips flopping around at speed. My daughter is only 12 y.o. and 85 lbs, but the same height as your daughter. She has skied since 3 y.o. (I'm an instructor), and always gets put in the highest level adult group lesson going out at our mountain (ie, level 7 or 8). She does not race.
This year, I put her on a pair of 155 cm Line FX7.3 carbons. These are a very light weight, light adult, all-mountain mid-fat (110/73/98) with a sidecut R of about 15 meters. She is absolutely delighted with them and her stability at speed has clearly taken a step up.
Line skis are not terribly common (I got a good deal on these), so I am not recommending that you look for an identical pair, but there are many mid-fat, all-mountain skis out there with similar sidecut radii. Among women's skis, you will likely find many that are appropriately light (to match her weight) and of a suitable flex (ie, softer than men's skis, more firm than junior skis).
Hope this helped,
Tom / PM