EPIRB, strobe, at least 3 red aerial flares and a couple of handheld ones. I'd also want a good signal mirror and at least a basic shelter kit. Signalling in an area like that would be too important to short yourself of tried-and-true methods, and frankly, it sounds like she was just flat out unprepared for the possibility of having to hunker down and wait a bit. 30 below is pretty extreme, but a sheltered spot and a small fire will get you through a couple days. Good emergency gear for that would still fit in a regular day pack, though I'd probably add a dry-bagged sleeping bag to my regular hiking emergency gear if that sort of weather was a possibility. The extra bulk would be well worth it in case of a leg injury or anything else that precludes getting back to the car right away.
On the White Mountains, aerial flares would be either a cruel joke or counterproductive. 100 mph winds would very quickly take it somewhere else in a hurry. Handheld flares would probably be more handy for quick firestarter, but it's not impossible for them to be handy. Under the specific circumstances of article, most useful aspect of a military strobe light would be to allow search team to more easily find one's corpse. Mt Washington and the surrounding mountains can have hurricane force winds roughly one day in three. Sending a helicopter into that is a quick way to turn one casualty into several. Helping rescue services more easily find your corpse might actually save lives. Orange streamer would be a good idea as well.
The lady apparently was well equipped. Just not enough for the area and weather she ended up going through. Snow hurricanes are nasty gorram things. It'll shred most consumer tents, and not a lot of hiker sleeping bags can deal with -30 temps. Large parts of the mountains are alpine, and don't have trees. Mostly moss, which doesn't burn well.
Best not to think of the White Mountains as yanno, nature. During the Winter months, think of it as an angrier version of the North Pole. With more interesting terrain. Oh, and lovely enough fact, during the winter, it is not terribly uncommon for the White Mountains to be colder than the North Pole.