The biggest problem with modern intelligent phones, specially apple ones, is that there is zero tactile feedback on the screen vs good old buttons or keyboard.
For an much more in-depth and eloquent discussion of touch screens and accessibility, you should check out this paper, slide rule which is the research that the VoiceOver design is based on.
http://openexhibits.org/paper/slide-rule-making-mobile-touch...
This is one of the few places where I give iDevices a lot of credit. Apple knew that touchscreens have certain disadvantages in that regard, and put a lot of thought into features that overcome those disadvantages. The result is something that's in many ways more usable for a blind person than a full-sized computer.
Source: A family member volunteered to help blind students for a while.
You may have a much better time with an iphone/ipad/ipod touch. The interface is much simpler than a desktop, and VoiceOver is much easier to use than JAWS.
Apps that can help (there isn't one catch all) Apple mail is pretty simple, and fully VO compatible Voice Dream Reader simple text to speech app that syncs with pocket, evernote, dropbox, and most importantly bookshare. a service for the blind with pretty much every book published on it.
Web pages are hard to navigate, but maybe some combination of pocket and voice dream reader will do the trick.
I'm going blind and this is how I perform the tasks you're talking about.
Unfortunately, if these solutions are beyond the means of your mom, there aren't many other options for the tasks you are talking about,
I'm working on an SDK that allows developers to add a conversational interface to mobile apps. This type of siri-like interface turns out to be much easier for seniors to learn than traditional assistive technology. You can check it out at conversantlabs.com
Feel free to message me if you want to talk more about helping your mom out.