Hey, sorry, but I've got something to add, or maybe correct myself a little. I had free time in the evening, so I closely checked out all the dialogues the MC had with both Ashley and Sara about Ashley and the sorority once again. I was curious myself, and it seemed to me that the guide isn't telling us something. The Dev assures us that the danger's passed though, and technically, that's what it is, the main thing's not to screw up and let Ashley out of your hands.
What I'm about to tell you (by quoting the text playing on screen) is that Ashley actually 'put it off for a while', 'took a little break', 'didn't completely abandoned this idea'... That’s more a yes than a no.
Now she has you and a little secret of both of yours. And when you keep her on the 'righteous' path (and it's in your best interest not to miss your only chance with your sex lessons), it takes her mind off things. After all, you actually replaced the sorority, which she needed in order to get what she's getting from you now. So even though the story doesn't give us a firm YES yet, I think everything will be fine (unless, again, we screw it up). Talking to Sara the morning after the incident in the locker room, the MC points out that it's not a good time to get too excited about cause the situation may still change. But during a joint workout with Ashley at the gym in v0.6.5, she admits that tensions between Carol and her make less and less sense cause the reason is 'faded'. And the picnic scene with Sara also gives us a breath of fresh air when the MC says it again that Ashley's 'given up on the sorority'.
So I still want to correct myself that the issue is in limbo. But the far we get into the development of a relationship with Ashley, the more pointless her desire to join the sorority looks.