Is a package your best option? I'd check some menus online and run the numbers to see; depending on your dining habits the dining plan may not be any kind of savings for you. I see three options:
1) You can always book a room-only reservation, buy tickets separately and pay out of pocket for dining. This option will allow you to include everyone one the room reservation but you can buy different tickets for the individuals (or no ticket if she really won't go to the parks at all). You might find a discount for the room-only, and tickets can be purchased through a 3rd party for a small savings.
2) Another option is a "ticketless package" which is not available online but you can call to book this. It would be room+dining for everyone, and buy tickets separately. Your wife would be able to use her dining credits at the resort. Ease of access and availability of dining options vary by resort, so do some research to find something that will suit her needs. I believe the deluxe resorts offer room-service; value resorts have just a food court style location.
3) A full package with room + tickets + dining. Everyone has the same parts (dining and tickets). Is there any chance your wife may join you in the parks for even an hour or two? Maybe for a meal? She would need a ticket to do so. This may not be your best option if she absolutely has no plans to leave the resort.
The Cabins at FW have a full kitchen, you could order groceries for delivery and your wife could eat without leaving. Some resorts have suites with a kitchenette, which may or may not be all that conducive to preparing a family meal but your wife could prepare food for herself. I believe DVC units have either a kitchenette or a full kitchen but I'm not very familiar with those options.
Enjoy your vacation!