Yeah, some warm layers to mix and match makes all the difference.
Silk undershirts/leggings, plenty of wool everywhere, and definitely a warm hat that she likes.
And, of course, a layer needs to be windproof
I get all that sort of stuff here:http://www.sierratradingpost.com/
While you're there, get some midweight SmartWool socks.
Warm, dry feet are so important, too- I live in smartwools 7 months of each year!