You can rev-up your wife's libido, get some relaxation and have a mini-vacation by interrupting your routine and "creating" a four day weekend in just two days.  The principal behind this "four day weekend" is this: when we get into our routines, our minds know what's coming up next; you kind of go on auto-pilot: your brain expects the next move and it is already two moves down the track.  As a result, time moves really fast.  So throw a wrench in the routine and gain some time your brain didn't know was there... 

Try this to have a four day weekend in just two days (if there are chores to be done, be sure to use 20 minutes each night Monday through Thursday to finish them as a team - there will be no chores on this four day weekend):

1. The set up:  This is where you jump start getting your mind into break-mode.  On Friday night, plan to have a couple of friends over for dinner.  Get some take-out food and set the table to make it nice, but not too much work.  Enjoy the break in the routine and watch what happens…
2. "Day 1".  Saturday - wake up early.  Yes - once you get past the groaning, everything will be fine.  Make your wife and kids some breakfast.  If you can't cook, try toasting some waffles and topping them with sliced strawberries.  Go do something out of the house - go to a park or something like that.  At this point, you will "feel like" Friday night was Saturday and you are in Sunday.  Go back home around 1:00pm and take a 45 minute nap (we put the kids down for naps, too). 
3. "Day 2".  After you wake from your nap, get ready for the new day as you would on any regular morning.  Then have some lunch and go out again.  I suggest something like mini golf or a movie.  Have some friends or family over early Saturday night for hors d'oeuvres just to hang out.  Now you will be asking yourself: "is tomorrow a work day?"  Get to bed a little early so you can have some alone time with your wife.  Get a good night's sleep.
4. "Day 3". Again, wake early Sunday morning.  Go for a walk as a family.  Go out to eat for breakfast.  We are fortunate to be able to walk about a mile to a good breakfast restaurant.  Do something fun - go shopping (if you find that fun), take in a matinee, something you and the family can do together.  When you get back, you guessed it: take a short nap.  Resets the brain.
5. "Day 4". - After you wake, take a quick shower with your wife (or not so quick if the kids are sleeping / occupied, if you get my drift) and get ready for the day.  By now you will be feeling like you should be at work, but you realize that you have the whole afternoon and evening left!  It is a good feeling.  Spend the rest of the day enjoying your family - get to bed early for that quality time with your wife.

After a couple of these four day weekends, your wife will be more relaxed and your connection will be stronger.  Of course, avoid fighting at all costs - and avoid talking about finances or work if at all possible.  Both of you will be less stressed and she will be more relaxed - she will feel closer to you - and her libido will be on the rise.  It can be very healthy for you both and for your relationship.