You can also deactivate corruption levels which would let you access previous versions of scenes. Though if I remember correctly, there is a version of Hily by the lake that should allow it.
Thanks for the reminder about toggling the corruption levels. I temporarily disabled Alex's pregnancy, and had no trouble bringing on Hailey's. I also maxed out Sami's available levels at the same time, but alas she seems to have a ways left to go in-game. I am definitely looking forward to seeing the rest of Hailey's pregnant scenes, and being able to officially get Sami to that point (incidentally, there is at least one Alex sequence that apparently still needs a pregnancy update, when you meet Hailey in the afternoon and the two of you find Alex in the woods while wandering--I am very curious how/ whether that will be updated for each girl's pregnancy). I am enjoying the game very much so far, so keep up the good work!