Is the severe Alzheimer's that afflicted my mother considered an expiation for her sins, and did she meet her Lord with a clean slate?

Alzheimer's disease, like other illnesses, is an expiation for a Muslim, based on the general statement of the Prophet, peace and blessings be upon him: "No fatigue, nor illness, nor anxiety, nor sorrow, nor harm, nor distress befalls a Muslim, even a thorn that pricks him, but Allah expiates some of his sins thereby." And whoever endures his illness patiently will attain the reward of the affliction and the patience shown through it.