You could get an inexpensive laptop and not enable internet on it, then use a USB drive for her to save/transfer documents to a main computer for printing. Or turn off/remove wifi from a laptop and require a wired connection to the network (so that it is used in a central location if needed.)
Likely thriftier with a bit more work is get her a RaspberryPi (
http://www.raspberrypi.org/ ) with a used monitor, mouse, and keyboard. She could even have the task of figuring it all out. A network adaptor costs more.
You can do fairly standard word processing on a tablet, but an external keyboard makes things much easier.
DS will get caught up on things and want to play a game or read a topic intently until he is ready to move on. But we are screen saturated, and that's the closest we've seen to addictive behavior. If you keep the door open on games, beware of games billed as "free to play" that are supported by ongoing purchases or ones requiring a subscription, both business models are supported by games intentionally designed to be addictive.
