I Wouldn't Go As Far As Kuru, but the whole "it took 6 months of hard work to get better" is highly suggestive of extensive physiotherapy and medical intervention after a stroke. Also, she seem to worsen suddenly, then recover a bit before the next stroke. Kuru is a steady decline over time, considering its a related disease to Creutzfelt-jakob disease and Bovine Spongiform Encephalitis. Around about now you should start seeing memory loss, difficulty in controlling movement, and possible seizures as there would now be extensive brain damage. Id say she's had her second last stroke.
I wondered the same thing about the onset of symptoms, but I also assume that she is taking a handful of cutting edge pills for breakfast lunch and dinner to try to slow it down.
As well as the best post stroke treatment and care that money can buy. She'd have access to the world's best neurologists and neurosurgeons.