Here's my opinion on a few women's pow skis... But you said shes 5'8", 130, I'm 5'2" 105, so that might make a difference in opinion, keep that in mind.
Pandora: This is what I ride, they are SO much fun. I ride these 90% of the time. They are amazing in pow, obviously. They are so light and the early rise makes a big difference, BUT I can also carve the shit out of them on groomers, for being so flexy and light, they are super stable.
Kiku: Personally, they were a little stiff for me. But I'm a bit smaller than your GF... They were fun skis though. I liked them for skiing shitty skied out pow, because they got through anything. VERY stable and tough.
VooDoo: I didn't like these too much. Might've been because they were too long when I demoed them, but they weren't good on anything but deep pow, an even then they weren't anything amazing, kind of difficult to control, but I'm guessing that was because of the length.
MissBehaved/Nancy: These were fun skis. They felt a little heavy in the pow but still fun. I enjoyed skiing these, they are a bit stiffer and heavier, but turn great and are super responsive. Great all mtn skis.
Those are all the ones I can remember skiing, hope it helps!
Oh and what you said about the 172 Pandoras being too long, I don't think it would be a problem. Like I said, I'm 5'2" on a good day and thats what I ride and I have no problems with them.
