One key characteristic of the Milly-Molly-Mandy stories is that storylines are kept to a minimum. Sixty years before Jerry Seinfeld made a fortune with a "show about nothing", Milly-Molly-Mandy was showing him the way.
In fact, the only contemporary genus that can really match these stories in terms of lack of plot is adult movies. In Milly-Molly-Mandy Meets her Great-Aunt, the arrival of a great-aunt is sufficient reason to write an entire story. In Jamie Loves Jeff, being in a kitchen is sufficient reason for the two characters to rip off their clothes and get down to it. Every Milly-Molly-Mandy features similar activities, characters and settings. So does every porn film I've ever seen. The parallels are striking.
Thinking about this, and because I'm a particularly sick and twisted kind of individual, I thought it might be ever-so-mildly amusing to create a fictional porn character, Milly-Molly-Trollop, and imagine what would have happened to her if she'd been placed in situations similar to those encountered by Milly-Molly-Mandy. Where Milly-Molly-Mandy is a sweet and innocent 5-year old whom everyone adores, Milly-Molly-Trollop is a 25-year old unrelenting nymphomaniac with silicon breasts who gets her rocks off at every opportunity. (The fact that such an individual would have been shunned and lynched in a village like that which Milly-Molly-Mandy inhabits is beside the point, it's not like porn storylines were ever renowned for their true-to-life quality.)