John
You've touched on a couple of things that would get my attention.

I assume that she has a Medicare supplemtal (Medigap) policy that should protect her assets from unexpected hospitalizations and outpatient visits...but you'll probably need to check the policy to make sure you're familiar with what it covers, and make sure there is enough liquidity to cover deductibles and co-pays.

If your mom has a Part D policy, then you'll need to make sure you have enough liquidity to cover the 'donut hole' in the event she should start to require several expensive medications

If your mom has neither a Medigap or Part D plans, I'd start thinking in terms of estate spend-downs and Medicaid.

As to LTC, you need to read and fully understand her LTCI policy. If it was issued prior to 1997 (and due to her age, I'll assume it was), then it will be of the non-qualified variety, which means it does not have to conform to the requirements of the qualified policies that are now issued, meaning it can restrict coverage, delay payments and do all kinds of things that today's policies won't allow. If you're not there to speak for your mother when she would otherwise qualify for the policy benefits, there's a strong risk that the insurer will not pay.

BruceM