i always thought this book was a real yawn, & my opinion hasn't really changed much in the last twenty years. it's the first jessi book, but jessi is, sadly, not exactly the most compelling character in the series. i was never into horse stories, ballet, baby brothers, or whining about being eleven, so jessi never really captured my imagination.
anyway--the A-plot involves jessi being hired on as a regular sitter for matt & haley braddock. the sitters haven't worked with the braddocks before, & there's a complication: matt is profoundly deaf. mrs. braddock coaches jessi on american sign language so that she can communicate with matt while she's sitting for him. haley is fluent & can help out, but apparently jessi is awesome at languages (much has been made in the fandom of her claim that she became "practically bilingual" after spending a week in mexico) & picks up ameslan right away. she likens it to dancing, because it is communicating through movement.
this segues into our B-plot--jessi is auditioning at her ballet school for a role in their production of "coppelia". she hopes to land a townsperson role, if nothing else, but shockingly enough, she instead is cast as swanilda, the female lead. a few of the other girls in her class are jealous haters at first. jessi feels bad, because she's the newest student at the school, & the youngest en pointe student, & she knows that there weren't a whole lot of black people wandering around medieval europe (when/where the play is set), so jessi being cast as swanilda is historically questionable. but she dances her ass off & the jealous girls in her class eventually have to concede that jessi is a great dancer (even though she claims, repeatedly, that she's not interested in being a professional ballerina).
the two stories come together when jessi meets a ballet classmate's sister, who is also deaf. jessi signs & asks if the sister is also a dancer. the girl says no, because she can't hear the music. jessi realizes that matt braddock has never been to the theatre or anything. she talks to mrs. braddock & matt's teacher at his special school for deaf children, & arranges for matt & his classmates to attend the opening night of "coppelia," with haley narrating each act & mrs. braddock translating in american sign language for the deaf students. the entire babysitters club, plus jessi's family, including her cousin, keisha, from new jersey, all attend the performance & it's a big hit. mr. & mrs. ramsey take everyone out for dinner after & jessi is sure to say that she orders ambrosia (sliced fruit covered in cocnut--ugh) instead of cherry cheesecake because she has to watch her weight for ballet. it seems really sad for an eleven-year-old to deny herself a slice of cheesecake after a huge, taxing ballet performance. but whatever. the babysitters are always doing things that have no relationship with their ages.
oh, the whole secret language thing--okay, haley is sometimes upset that hearing kids in their neighborhood make fun of matt or think he's weird because he's deaf. she gets sick of defending him. so jessi spreads the word that american sign language is like a secret language, & the kids around town get excited about learning it. that way, matt makes friends who can sign with him, freeing haley up to make friends of her own without having to constantly look out for matt. the pikes all want to learn how to sign, & the triplets & nicky become friends with matt, while haley makes friends with vanessa. when shit like this happens, i imagine these kids filling out their college applications in ten years. knowing ameslan isn't a bad thing to have on your CV.