What to Look For
It's obvious that a big family needs a washer and dryer with large capacity, but other functions are helpful, too. If your house looks like a rerun of the Brady Bunch, here are some features that might help you find some time to actually relax!
Sanitizing function If you've got little ones at home, they're going to get dirty. Look into a sanitizing washing machine like the Electrolux EIFLS551 and LG WMH3360H -- both of which can clean out any stain you can imagine, and even those you don't want to think about. They're a must if you use cloth diapers!
Dryer cleaner It sounds redundant, but after a lot of loads of dirty laundry you'll need to clean the inside of your washer. Consider a washer with a self-cleaning function, like the Whirlpool WFW94HEX
Short wash and dry cycle times If you're doing several loads of laundry per day, look for a washer and dryer that wash quickly. Not waiting an extra five minutes for a wash cycle to complete will save you lots of time over many washes.