Has she considered Trigger mitts, bit of both worlds?
And the reason you need Gore or some similar breathable membrane is that your hands have twice as many sweat producing pores than any other part of the body, each hand produces enough millitres of moisture to fill a small vial every hour, hands are basically temperature controllers for the whole body, so when its working they are trying to cool it down hence how they get cold, quicker than anywhere else in action sports. It is one thing, like boots, that is worth spending good money on, cold hands can ruin your day.
I know all this from years of being a successful Glove and Ladies Handbag salesman.
Because like all Brits after a good days ski/snowboarding you go to the bar, get pissed and leave them behind and have to buy some more to keep folks like me in business… 😉