I made a couple modifications, eliminating the tapering at the top of the bag and making only one gusset. Although the pattern is originally intended to be a pencil case, with the wider top it's the perfect size for toddler toiletries. Having one gusset keeps one side secure while giving you room to rummage around on the other side. With two gussets the bag wouldn't open nearly as wide.
Although I'm getting better at adding piping, I'm still not great and the seams each took a few attempts. It's worth it though - the bag wouldn't look nearly as nice without piping. Despite some fussing with the piping this bag only took an afternoon to make. I highly recommend it!
I used one layer of batting and two layers of medium-weight interfacing for everything except the gusset. If I make this again, I would use heavy weight interfacing so the bag holds its shape better. The parka zipper worked out great - easy for little hands to open and close.
