Just wanted to let you all know how my trip with my mother-in-law was. We were at the parks July 15-18. It was HOT. The crowds were moderate to moderately high, for the most part. I rented a wheelchair (manual, lightweight, 19 in seat) from Shamrock Medical. The charge was $30 for 4 days, with a $15 delivery charge. The wheelchair was there at bell services when I arrived, and we left it there for Shamrock to pick up when we left. It worked perfectly, it was not heavy to push, even in the hot weather.
At first my MIL was a little taken aback that I had gone ahead and rented the chair, but we just took it with us (I told her I would use it to carry our backpacks) and within a couple hours of walking and waiting in line, we knew we were VERY glad that we had rented it. The first ride we went on was Toy Story Mania, and the line was about 40 minutes and it was really hot and humid. She never would have made it standing in the heat for 40 minutes. (It was so hot my eyelids were sweating). It was great to ALWAYS have a place to sit down, no matter where we were. We put our backpacks on the back of the chair, so that helped as well. A lot of the time she just walked, and sometime we would just park it and then come and get it later. While waiting in line, when her feet were tired, while waiting for WOC or even Muppets or Bugs' Life, it was great to have a ready made place to sit. She even took a little nap while waiting for WOC.
There were a few times that it saved waiting in line (Fantasyland and Nemo - although Nemo was still quite a wait) but most of the time we just queued with everyone else, she was just thankful not to have to stand all that time.
It was especially helpful heading BACK to Disneyland Hotel at the end of the day. I am glad I rented one from outside rather than in the park, because I didn't have to leave it there when we were tired out.
We were shopping in World of Disney, and an older woman with a cane was buying some collectible merchandise (and you know how slow those cast members can be) and she was getting very tired, so I offered to let her sit in the wheelchair while Mom and I were shopping. She asked where we got it, and she had her son come over and take down the information so they could call and rent one the next day