She may be willing to due to this being a more active trip. I'm planning to take her a day early depending on room rate, so I think that will help.
I think that arriving a day early would definitely help. If nothing else, it would give you an extra day to adjust to the time change, assuming that you're not already living on the west coast. When I did this trip in June, I found myself waking up very early for the first day or so just because my body still seemed to think I was in the central time zone.
While I'd agree that the first two days aren't very active, once you get to
Disneyland, it's pretty similar to being at Disney World, where there's a lot of walking involved. Imagineering didn't have as much walking, but there was a lot of standing.
One other consideration is that, if you choose to do things like fireworks and Fantasmic, there are a lot of late nights followed by early mornings. On our trip, there were also a lot of options to do things with the group during the "on your own" time, and many of them were hard to pass up, so there may not be as much free time as the "official" itinerary indicates depending on the choices you make.
The nice thing about the Disneyland is that, since you're staying at the Grand Californian, it's very easy to go back to your hotel room since it's so close. Your mom would miss things if she did this, but she'd always have the option of going back to the room to rest and then meet up with the group later. We had several members of our group who were "under the weather" (back problems, a bad cold), and they did this very easily. They just talked to the guides who told them when and where to meet us.
This is an amazing trip; I think your mom would really enjoy it, so I hope the two of you are able to make this work.
