He’s off a bit there. They stopped the show with the end of Book 6, right before the time jump for Book 7. So they didn’t make the final 3 books into the show. There’s hints and foreshadowing for them.
Also the books don’t directly correlate with seasons until Season 4.
- Book 1: Season 1 and first half of Season 2
- Book 2: Second half of Season 2 and first half of Season 3
- Book 3: Shortened and only the second half of Season 3.
- Book 4: Season 4
- Book 5: Season 5
- Book 6: Season 6 (but only 6 long episodes)
The fact that 5 kids knew well enough about the OP’s vegan status to use them as an example meant that the person probably never shut up about it.