As per Rainbow's request, Emily spent most of the school day without a nappy.
My original fear of her bowels having their own way on the ride to/from school was for naught, as the "nappy-less" experiment was to begin once she arrived at school, not on leaving home.
From what we've seen, things worked well today. Rainbow asked us to check if she was dry (or more exactly, if her nappy was dry) when she got home. Which it was.
Here's hoping this is the start of the end regarding potty training. It's been a real pain in the arse.