I know that it was clearly showing her only handling the onion with her fingertips, but I still feel like rubbing her eyes with the heel of her palm like that wasn't the best thing to do.
With only 9 chapters released, there really isn't enough data to say it's random. Thankfully the official raw site lists the publication dates, so you can see chapters 1 & 2 were released together on 5/28. Then 3 through 7 released weekly on Thursday between 6/4 and 7/2. There was a...
If you feel strongly enough to say that line, then just come out and fucking say it. Either that, or go full l33t sp34k and replace all of your vowels with numbers. This strange self-censorship doesn't serve any purpose.
Sure, Ono doesn't have the same extreme bust the other two have, but she's far from "flat as fuck."
It certainly could be a possibility, but I also feel like pages 4-5 of chapter 1 would have included that information if that was actually the case.
If you set aside the branch family aspect of it, it almost feels like it could have been slotted in far earlier as a kind of "monster of the week" entry, instead of way down the line here in volume 7.
You might try https://mangadex.org/title/aa50b79c-3f43-4b78-a288-a5da22119599/solving-queen-ophelia-s-mysterious-death
I found it to be quite concise and enjoyable.
Largely distracted in this part, because I'm not entirely convinced that she would be able to interact in those ways with her shackle; and we should be able to see Cleto's own hand in the panels of her handling his junk.