Adding on to all the rest, (and this isn't explicitly PA, this is federal) she may find her healthcare costs are more covered by a Medicare Advantage Plan (Part C plan) rather than Original Medicare (A&B). (Note: this is NOT the same as a Medigap plan.) They're basically plans with private providers and, surprisingly enough, they almost always cover WAY more than A&B. Some of them have a more limited treatment network (but no more restrictive than a standard HMO or PPO), or they won't cover out of area unless it's an emergency, but if you're not traveling a lot, it's not really a problem.

Ex. I'm on Medicare (and SSDI, but my income is lower than hers) and my plan (an AARP Medicare Advantage plan - you don't have to be part of AARP to get the plan, I'm not) has a $0 premium, $0 deductible. I pay $0 copay at PCP, and like $20-30 at specialists. My plan includes a bundled drug plan (Part D, although you can get plans w/o a Part D plan and pick a separate Part D plan) and, with Extra Help/the Low Income Subsidy (LIS) I pay less than $5/Rx (and that went up recently). They even cover eye and dental! I think they also have a hearing aid allowance. Plus, I think they can even provide transportation to appts and stuff.

I used to have Original Medicare (A&B + D) and did an Employed Individuals with Disabilities thing so I could have Medicaid on top of my Medicare to use like a Medigap plan, but with this Medicare Advantage plan, I don't need the Medicaid on top and just have this.

You'd want to use Medicare's comparison thingie to compare different plans for her needs. You can even say "only give me plans that cover all my meds" so you can make sure her meds are covered or sort by premiums (at her income, she'll probably have some premiums, but they'll probably be pretty low) or deductibles or other things. There's also people you can call and talk to that can help you sort out plans; those folks don't make more if they sell more of one plan than another so they're not going to push a plan that doesn't work for you.

I hope this helps.