MDE is only in the Apple App Store (iPads, iPod Touches, and iPhones) and on Google Play (all Android phones and tablets). If she doesn't have one of those, she can just use disneyworld.com on her mobile browser. From there, she can make ADRs and FP+ selections and view plans and showtimes for the day. If she wants wait times, easywdw.com/waits offers the wait times direct from MDE.
You can install it, but you first have to install a hack to the root directory which voids the warranty and tech support and has to be repeated every time there is an update to the Kindle OS, so I wouldn't recommend it.