I'm also not a fan of Apple. But that being said, I do think the iPad and their computers are good for non-technical people or those that just don't want to worry about keeping up with updates, typical virus issues, etc.
It boils down to the main uses. If it is just browsing, email, ebooks etc, it is a good choice. Plus there is the installed word processing, spreadsheet, calendar, contacts,
Case in point, I have a neighbor that recently purchased an Apple desktop pc. He's very happy with it. He's older, though age isn't a factor in who can use a pc. He's been through 2 windows machines over the past 6 years. A big part of that is not keeping it up to date, but he just didn't want to deal with it. He just wants to turn it on and browse, email and games.
Apples are expensive. But I'm told part of that cost is for the after sale support they provide. In my neighbor's case, he purchased at a local Apple store. They sat down with him, went through everything and made sure he was comfortable. And he's called them with questions. You'd have to know him to realize the $$ value of this after sale support.
If there is a local Apple store, have her go and try one. I'm told they will let people "play" with them in the store for quite a while without pressure. Of course others may have different experiences.
If she does decide on an iPad take a look at Apple's refurb store. http://store.apple.com/us/browse/home/specialdeals/ipad
Looks like they have different generation units available. Maybe she doesn't need the latest and greatest. And they warranty them.
I've also been hearing things about Chromebooks lately. Not sure if that includes a tablet version. Supposedly an easier to use Android device. Might look at those.
Good luck with your mother-in-law's decision.