One quick thing to note for your Mom: She can park the
ECV and walk through shops, or ride/attraction queues, or to your table for meals; she does not have to drive it anywhere she does not feel comfortable.
Most of the table service dining venues will ask you to park it outside anyway; if she really needs it to get to the table, they will try to clear a path so she can drive close to the table, and then you or a CM will remove it from the dining room.
A folding cane will be a great helper to bring along; takes up very little space, but is very handy when you need it!
If you are working with a mobility device, a good quality doorstop for the room is so handy; personally I like
this one at
Amazon; you can often find it locally at
Walmart and Ace Hardware, etc.
Personally, I vote for the monorail hotel! This sounds like a really special trip - you and your Mom, and I know you will be banking memories of this for the future. I took my Mom on a trip like this (with my daughter, so it was 3 generations!) and it was singularly the best trip I have ever had to Disney World. We laughed so much, and had so much fun, and I promise you that when we lost my Mom, I was so grateful that we went, and had so much fun. It cost more than we anticipated, but we ate great food, and we did some shopping, and we rode rides, and just goofed around together, and had so much fun, and to this day, I look back at those pictures and smile every time. Time together - and the memories you will make - are truly priceless. Give yourself - and your checkbook - permission for one really fantastic trip that will stay in your heart forever.
Now, I know - CR is stupidly expensive, unless you happen to snag a deal on a Garden Wing room, and I think those have evaporated with the 50th, and the return of post-COVID travel. So...
...GF is usually the most expensive when we travel, which leaves Poly. It is - by no one's measure - a "bargain", but it is the least expensive of the 3 Monorail Resorts.
There is, however, a Deluxe that is a "hidden" Monorail adjacent Resort, and I am talking about Wilderness Lodge. Hear me out - this is my reasoning:
WL is easily accessible to MK by *boat*. (We can talk about boats and
ECVs later - just follow my logic for a moment LOL) You can boat directly to the MK docks for MK day, and for EPCOT day, take the boat to the MK docks to either take the Ferry to Ticket and Transportation, with the EPCOT Monorail from there -or- just hop on the Monorail and change trains at Ticket and Transportation.
But, maybe you are not in a boat mood. That's cool. You can still take the bus from WL to MK, and you can still ride the Monorail from there! You can ride it just for fun, and hop off at every Resort to visit, or you can ride it to EPCOT.
WL is *so* lovely; it is one of my most favorite places to stay at WDW. The food is fantastic, the rooms are recently renovated, and it is singularly quiet - you really feel like you are tucked away in a lodge in the piney woods.
But, it also has all the features of any of the Monorail Resorts, including the Electrical Water Pageant! You can see it from the docks, or Geyser Point, or even some of the rooms that have a lake view! And because the Resort is relatively compact, there is one bus stop, and no one has to walk super far to get to it.
It's just something to consider - my second choice, hands down would be Poly. I love that stinking' old place; it will always have a very special place in my heart as well.
And if you want a Moderate level, I would strongly suggest POFQ - smallest Resort on property, quiet, and you can ride the boats to and from Disney Springs. It is about the most centrally located Resort as well; the average bus time to any Park from there is less than 30 minutes - it is literally right across the road from EPCOT (although you cannot walk there; there is no sidewalk) The QuickServ food court is charming, with several not-so-hidden nods to "Princess & The Frog", and in the evening, there is a great jazz combo that plays in the bar. Also, beignets. Just sayin' is all.
But whatever you decide, I just hope that you and your Mom have a wonderful, memorable trip together. Take a million pictures, and act your shoe size, and not your age! (((hugs)))