directly to display "TV" and "Films" (these being two of several video folders on my NAS)?.
Yes but do not use folders on your nas as a reference. If you want really simple (like no genres or stars or directors) - just the name of each movie and TV show:
Set up two views for her in theater view like you want her to see. Remove everything else except "Video" in the options - change that to a secondary roller. and use the Nest button to put the 2 views under Video. After following what Jim said, JRiver will open in theater view and all you should see is Video and underneath it the two view choices. If however you need to separate TV into Series, season and episode .. you would need the TV View to include those categories and she would click and then make her choice. This is cooler, just make sure your files are tagged correctly (or rather consistently). I'd backup the library before you do this.
I presume you are just going to "restore" your library to her PC? Did you know you can set up and save Standard Views (which can be imported directly into Theater View via the options). That allows you to just copy them over to the correct directory on her machine. I do that a lot when I'm trying to set other people's systems up. Might not be as fast initally, but its good to know if she wants different Views you can import them for her later without redoing her settings.