For others who are concerned about this range of problems, consider the following issue carefully: elderly parents who for whatever reason compromise their financial and/or physical health are placing a direct burden on you. Although their debts do not transfer to you, you may very well be on the hook due to familial obligations. E.g. your MIL gives up all of her assets to a fraudster. You cannot bear to see her homeless - so you step in financially. Her actions are now reducing your wealth and quality of life.
One solution to this is to anticipate and discuss issues well before they arise. Transfer assets to trusts for grandchildren. Create living trusts where a child is a trustee. Watch your parents' financial accounts. Talk to them about common scams [Nigerian/IRS/Gift card/Email]. Train them to always confirm with a family member before transferring money anywhere.
There is also the option of pursuing Guardianship and Conservatorship should that become necessary.