The way her mother described her "talking a mile a minute," and jumping from one topic to the other in a series of phone calls doesn't sound like a stroke to me. It sounds like a manic episode or a symptom of a mental health disorder.
Also her mention of the matrix makes me think she was experiencing some kind of psychosis or hallucinations.
It's possible that it was brought on by drugs, but didn't she have an event to go to and a reward she was about to receive?
It's hard to say because we don't know anything about her history or if she used drugs, but it sounds like it was a long drawn out episode for drug effects to last that long.
I'm sure LE will be questioning the last person she was with and hopefully will get some answers. Imo
She was scheduled to fly on Mon and the award event was on Wed.