To all those concerned, an update:

Grandma had a stroke—a blood clot in the brain—which eventually burst and caused an open bleed in her brain. Though she can move her left arm and can move her head a bit, all other bodily functions are beyond her scope of ability, and that goes for everything from speaking to using the bathroom. She will remain in ICU for a bit longer, and then will be transferred to an assisted care facility to live out what remains of her life, which feels like a very sad, sad thing to write.