If you want the wife to participate in camping, you'll probably want a tent with steep walls - much more roomy inside. As you'll be driving to your campsites, weight isn't an issue. Now, if you were backpacking in, that'd completely change the recommendations. Backpacking = spend lots of money on a really good, light weight tent; the smaller and lighter (but large enough to sleep in) the better. Driving to a campsite = much more flexible, and potentially less expensive.
Also, another option = 2 tents... one for the kids, one for you and the spouse. We had a smaller 3-4 man tent for the boys, but a 10 man tent for me and my wife... We had one of those inflatable queen size matresses - the kind that comes with a stand, rather than sits on the floor. By the time we loaded up the tent, it was as cozy as our bedroom at home. However, on canoe/hiking trips; that one wasn't an option.
Also, for what it's worth, you can often find used pop-up campers for $300 - $500. Complete with a little kitchenette, etc. We purchased a 25 year old pop-up in mint condition a few years ago... The colors are orange and yellow - 70's ish. So, we completely equipped it with 70's style things inside... right down to those cheapy yellow, orange, and green plastic plates they sell at Walmart. It's quite enjoyable.