The best thing you can do for your weary wife is to take your crew, minus the smallest one, (or take them too if they are old enough to leave!) and leave your dear wife at home alone. Alone. No noise, no mess making, silence, ability to eat with out having it coveted, peace, unplug the phone, make sure there is something she loves to eat, calm, a good movie, a good book, no expectations of her cleaning the whole house, no complaints or whining about how hard your day was with all the kids (duh), serenity, stillness, no demands or questions......the list could go on.
Take the kids to a friends or camp or go to Chicago or some such place, and juggle the kidlets and perhaps spend the day praying for your wife and thanking God it isn't your vocation to do what she does.
You don't have to spend the family fortune to do this for your wife. Hotels with water parks might work but even just finding some sweet family who will take you all in for a day or so might keep your wife out of the funny farm. I personally am not quite so thrilled with being taken out to eat so I don't have to cook as the offspring are usually at home killing each other and trashing the place and I still have to come home to a disaster. (so........trash a friends home? That is what friends are for).
Seriously, I am SO enjoying my afternoon and wonder how I can convince dear husband to stay away till this evening. I miss my Anna already but she has her own stuff to take care of and existing here won't get that done.
Remember.....no whining at your wife about your dear darlings behavior while you have them. She needs a break from whining as the foremost skill of the sinful human race is whining and sometimes it is nice not to hear it and know that her rest came out of love and concern for the wife. Ahhhhhh..........solitude. I remember that.