While I agree that the Canon Elura 100 is a great entry-level camcorder (I have one), I will say that it's probably not the best one for your mother. I would suggest getting a DVD camcorder instead.
I say this because of your description of what your mother will be doing with it. Most important was "easy to use" and "easy to play back". While miniDV is easy to use, playback is another issue. With miniDV you'll need to connect the camcorder to the TV's composite inputs, rewind the tape, find the stuff you're looking for, play ... OK, not rocket science, but it's still pretty involved. So now you've watched the tape ... make sure you FF back to the spot where you left off, or you'll end up recording over your previous footage. BIG TIME PITA!
With a DVD camcorder, you record stuff to the DVD. When it fills, you finalize the DVD. Then pop it into the DVD player. Simple.
There's no risk of recording over previous footage. No rewinding. No FF'ing. Easy as pie.
The quality won't be as good as miniDV, but on a standard TV, it won't matter too much.
BTW, is this grandson your kid? If so, you should get a nice HDV (or AVCHD) for yourself. The stuff that you record should be in the highest quality that you can afford. After all, it's for prosterity.
ft