Wives that think roughing it involves staying at Motel 6 are tough to please when it comes to even car camping. BUT ...anything you can do that will enhance her experience is your only shot ...and we all know that once they hate it there's no going back.
So ...that said ...you are now only limited by your wallet and available storage space in your transportation vehicle of choice for this trip.
I'd go with the most comfy sleeping arrangements and a roomy tent.
For car camping getting lightweight stuff has merit only from the standpoint that if you progress to backpacking or have (want) things small and compact for future trips you won't have wasted money ...but kitchen chores are much easier with Coleman Propane stoves and lanterns....and if you progress to using smaller stuff someday, you can relegate these items to your disaster kits and backyard camping etc.
Choose food that simplifies the meal process..not too many pots and pans and ingredients that keep well in an ice chest.
Make sure the kids have stuff to do if it rains ... or when you are tired of chasing them around the campground. Spaghetti, Mac 'n Cheese, hot dogs, burgers, steaks, pork 'n beans, chili etc ... you get the idea.
If you're thinking of taking short hikes....consider water bottle carriers for everyone and bring bottled water.
I have always liked car camping ....and bring more creature comforts each time. Lounging around the camp fire is great, especially after the kids had collapsed for the night. If the wife has a favorite special beverage this is the time to break it out. If not, or she's already given up ever doing this again, make sure you have one for yourself.
Quiet parks, are best, since rowdy neighbors tend to make for a negative experience. And a short quick trip ...a couple days .. is better for the first time...that way if its really horrible it doesn't last long and your shortcomings in planning due to budget or "I shoulda thought of that" items won't require "doing without" for a long time.
Good luck recruiting the spouse ... but if she doesn't want to participate in the future it can become guy thing with your kids ... which can be a great bonding thing...which is always good.