The weight gain thing... yeah, Anna, pretty sure that is just you continuing to grow because you're a young teen with tall genetics. I'm still convinced she has too high of a metabolism to build up any undesirable body fat, at least for the time being, due to her tall genes from her dad, and that it also explains her gluttony as a byproduct of a strong appetite to feed that metabolism.
These are things I know are real because I have experienced such a metabolism personally, and my eldest sister has also attested to being able to eat at lot in her young teen years, as well, without it showing on her figure.
Anyway... looks like when Anna mentioned shabu, she probably meant:
https://en.wikipedia.org/wiki/Shabu-shabu
Basically, looks like it's that nabe/hotpot stuff that she made for her and Kyo during his first visit to her place.
Not surprised that, at least as far as Kyo can tell, they meet 'by chance' before and after school... Anna obviously makes an effort to intercept him, but is trying to be sly about it. Moe sees through it, though.
And yeah... all those people claiming she'd be into Kyo, yeah, nah, Moe doesn't acknowledge his existence in that respect. And as much as one might say the 'scum on the inside' lines up with her response at the end of that 4th grade story just before this, she seemed legitimately bothered by his side of the story to the point it's not attractive to her, which was reinforced by her continuing to insult him and refuse to acknowledge Anna's assessment and question the thinking of
both of them.
Anyway, looks like people really did get fooled by Moeko's dramatic performance about her brother being hospitalized. It really did seem way too exaggerated to be an actual crisis, and was just an excuse to run away once Kyo and Anna had met up so they had alone time.
And Chii continuing to be Chii...
If Anna was forced to give a number, it'd probably be 100, or essentially 'off-the-scale' because of how much she adores Kyo.