But hear me out. I find curious that at page 8 she says "Yuki... and the rest...". Isn't it weird she mentions Yuki twice? Why not just saying "I know you wanted to hang with everyone"? However, she makes emphasis in Yukihira. I can't really help but feel like Miya knows more than what everybody assumes.
Not that it makes me dislike her, I'm from Miyahara gang anyway, so I'm rooting for her. It's just this chapter's pointing out how perceptive she can be.
Anyone saying that Miyahara doesn't like Arima romantically are just Yukihira bros in denial of what's coming. The manga doesn't help itself with such Nisekoi-like snail pace, but it's there.
Miyahara's feelings are subtle. I believe everyone can see she does know way more than she usually shows. Miyahara probably likes Arima ever since that flashback of Arima, his sister and Miya as kids. However, for whatever reason, she maintains a oblivious and bubbly persona. She definitely isn't oblivious and gave some real hints until now (looked a bit odd after the eraser thing, the beach scene, the umbrella scene, the upcoming scene of chapter 40 with
"when we get married-" - followed by a pause and then, "when we get married to other people, our families will still be close, right?" while making a upset face which contrasts to all of her faces until now.)
Actually, it's genius not focusing that much on the manga's female MC because her inner thoughts would basically answer the plot.