In Kristy's Big Day, the BSC has been in business for nine months now; it's the end of the school year / almost the start of summer, and the biggest thing on Kristy's mind is her mother's approaching wedding. If all goes according to plan, the Thomas-Brewer wedding will take place on the third Saturday of September, a month after Kristy's thirteenth birthday. But since the book is about the wedding and takes place in June, it should come as no surprise to anyone that things are not going to go according to plan.
Before too many pages have passed, the wedding gets bumped up from months away to only two and a half weeks away, and the Thomas-Brewer clan have to scramble to make arrangements. Turns out, as the blurb says above, that the BSC is going to have their hands full for the week leading up to the wedding itself; they're going to be taking care of fourteen children, including babies. They'll be compensated--$600 to split between them--but... they're also only twelve themselves, so it's a daunting task. A task, one might argue, that five twelve-year-olds aren't capable of handling. Except, of course, that these are the most organized, ambitious, and capable twelve-year-olds in the world, apparently. Hooray for fictionland.
What follows is a solid 150 pages of slightly older children caring for slightly younger children, and I have to admit that it doesn't make for the most fascinating reading. There's something a bit charming about it, but that might just be nostalgia on my part; I have no idea if someone who didn't grow up reading The BSC would find these scenes even remotely interesting.
In the background to this marathon babysitting, there are a few elements more typical of a "recently blended family" plotline. The story gives some focus to the interactions between the soon-to-be stepbrothers and stepsisters (in order from eldest to youngest, these are Charlie Thomas, Sam Thomas, Kristy Thomas, David Michael Thomas, Karen Brewer, and Andrew Brewer); of note are a conversation between Kristy, Sam, and Charlie that boils down to "In what way is our stepfather our father?" and Andrew's obvious need for some extra emotional support during such a life-changing event.
Personally, I liked the book. Like I said, it's not the most interesting subject Martin ever covered, but the entire BSC series, including Kristy's Big Day, has a certain charm to it that I really appreciate and definitely enjoy. It's not a genre or even a subject I can say I'm fond of, but it's fun nonetheless.
If you're looking for MG, realistic fiction or chick lit, or some 80s/90s nostalgia, I definitely recommend giving The Baby-Sitter's Club a chance, if you haven't already.