Quark is hardly entry level or even intermediate. It has a pretty steep learning curve (as does InDesign) unless you know a lot about what you are doing and have some experience. If she is not all that computer literate, then she is likely to be overwhelmed with Quark.
I would suggest she work in Word. It is highly unlikely she will need to do anything more than it is capable of doing. If cost is a factor, then check out something like AbiWord.
Another option is Pagestream, which I've used a few times over the years. It's a lot cheaper than InDesign but fairly powerful. It's also fairly easy to pick up... I've known folks with little experience to do well using it.
In your quest... please don't overlook Scrivener...
Designed for use by writers of all kinds, Scrivener is a virtual writing studio that integrates the processes of outlining, storyboarding, research and writing. It's a notebook. It's an outliner. It's a cork notice-board. It's a ring-binder. It's a place to store and cross-reference your research. It's a basic word processor. From first idea to first draft: