Louis Vuitton Neverfull GM: This tote bag is ridiculously durable for a bag made of mostly canvas - not to mention, super easy to wipe off when the kids get a hold of it or we happen to spill wine.
This bag holds up so well, it is one I would recommend getting secondhand if you are interested in the style and in saving a couple hundred dollars on the price tag.
This YSL bag comes in several different sizes and I would recommend the large for all of the motherhood essentials to fit in your sac du jour bag. I have the smaller one (pictured above) and wish I had the bigger size for this very reason!