By the way - my mother re-did her arrangements after my father died. Things she did right:
1. A Trust which allows me to handle most of her finances and other external needs.
2. A Power of Attorney (POA) that was immediately active (as opposed to needing a doctor's certification) that allows me to handle the rest of her finance needs.
3. A Healthcare Document that allows me and my brother to lead her care when she is not able to make decisions well.