In a post-apocalyptic novel I'm writing (which is the subject of many questions I've asked on Writing.SE), I recently cut out my entire Chapter 10-11. I was revealing the MC, Eris' finékinesis (death-force manipulation) to her love interest, Caspian, and her accidental killing of his mother and her own family, but in the middle of writing it, I realized that it was probably too soon, realistically, for Eris to reveal a part of her past that she'd blocked out after knowing Caspian for roughly a week.
At this point in the story, however, Eris' own actions are becoming more obvious to her, and my beta readers also understand that Eris is the one who killed both Caspian's mom and Eris' family. I just don't think it's the right time to reveal this to the characters, and I'm faltering a bit on identifying when is a good time.
If this helps, according to an eight-point story arc, I think my story is moving from the quest stage to the surprise stage.