Having also peeked the raws
I don't think it's A-Cup Angst, at least if you mean the second half of the chapter. From a tiny bit of not particularly successful translating attempts at some of it... I think she's worried about and wanting to get used to breasts in general, wanting to get used to seeing and feeling them, possibly set off by Aoi groping her at the start of the chapter, because I guess with her keeping separated from other girls, she's probably not seen anyone but female family members (and herself obviously) naked... then at the end of the chapter she tries to google what normal breasts should be like, gets age-walled and self-destructs
