The last speech bubble, I tried my best but I really can't suss out what she's really saying. I took a swing at it, from what I could make of it, but I'd appreciate it if somebody could check it.

Edit: I think that it's, relating to the second bubble from Miku, and the line on the next page, she's jealous that Miku will be singing "other songs", since her song hasn't been finished yet.