Glad she made it out. In a situation like that it's easy to compound a bad situation with bad decisions, leading to worse outcomes.

Three days in the snow with a garbage bag shelter is not a lot of fun. You either freeze or sweat, and as your insulation becomes damper and damper, you do both. Miserable.

She was alive, but had to be treated for frostbite and hypothermia. No doubt she'll have more than a garbage bag on her next hike.