I am annoyed that I couldn't figure out what was keeping her from giving birth. After I finished Ophilia's current content, I then jumped ahead 90 days just make sure it was time or anything related to that. Ran around having every discussion I could think of that might be connected. Ultimately I just went into the switches via RpgMakerSaveEdit, clicked off "Kate Belly" and clicked on "Kate Baby". I am not completely confident that it fixes all issues, not knowing how that effects the Kate nursing the baby for a week, or the discussion about keeping the child.
But, I edited those switches, loaded the save. Kate was there talking to Rick without a belly. I skipped ahead to midnight, talked to her and she said that the baby needed her right now. Which is what she should say. I went and slept at the MC's house. Walked out to Rick's morning spot. Then saved. Save attached.
I then talked to Rick and we built the next stage of the cart. Which told me that it is probably fixed. To save yourself in-game time, on Thursday night after Ophilia goes to bed lockpick into her room and talk to her. (If you talk to her Thursday day, she will tell you to come see her at night. Don't rush the sex, ask her, then fuck her.)
Side note, that made me chuckle. After I first loaded your save I tried troubleshooting by looking in the relationship status to see that things were probably advanced. I noticed "lost virginity to M---". I was like "who the heck is M---???" What weird story path have I missed. Once I realized it was you, I felt dumb but thought it was funny.
*** I realized I may have muddied the waters, this save is just the day after yours. The switches are edited, no relationships are advanced. Wait for Rick to walk up to the dock, talk to him.