And given her behavior, I get the sense that she was just waiting for the dream to end and for Midori to go back to Tazune.
There prolly was a little of that. Midori is a dreamer, but Maki is a woman with both feet solidly on the ground. The idea that Midori, once their little escapade was over, would cave under social pressure and return to her "husband" Tazune was not at all unreasonable and could not be discarded just like that. It would be understandable for Maki to hold such fears.
Of course, those fears were blasted to smithereens once Midori proposed.
By the end of the chapter, we see them making plans for their future together... in particular, how they will deal with Tazune and whether Midori alone or both of them together should go tell him that he has been dumped.
She still loves her, but she has no faith that Midori will stay with her.
Hello? PROPOSAL! All doubts has been cleared by the final pages!
I don't think I explained my thoughts very well. At the point in the story where I am suggesting that she might have contacted Tazune, she had no faith that Midori wants an actual relationship. She thinks she's just running away from a difficult time in her relationship with Tazune. The proposal is the first moment where she starts to clue in to the thought processes that we've been seeing from Midori. I'm not saying she has zero faith at the end of the chapter, I'm saying she had zero faith through like, page 30.
That said, I wouldn't be surprised if she still had lingering doubts that need to be squashed. And what better way to squash doubts than by having the two of them weather a crisis moment together? Midori needs to understand how insecure Maki has been about her feelings, and they really need to affirm their relationship at this point.
I for one I'm glad Tazune showed up at the station. I didn't like one bit Midori's decision to go meet him all by herself. It looked to me like a direct route to a big domestic violence incident. Thank goodness, now the asshole will have to deal with both of them at the same time. And in a public place, too. Better a hundred times than having Midori face Tazune alone, one against one, in an apartment that belongs to him.
Eh, there's drawbacks to this, too. Best case scenario, Maki isn't responsible for his appearance, in which case....well, that's pretty fuckin' scary, right? Conveys to Midori that "Hey, no, you can't confront him in private on your own terms, he could literally show up anywhere you are." It also shows that he is willing to fucking stalk her to claim her, which is somewhat dangerous behavior. Guys like Tazune also don't respond very well to public shaming.
But I agree, this was gonna happen anyway, and it's better if it doesn't happen when they're apart.
Unless Maki is the one that called him, in which case the next chapter is gonna have feels. ;p