Christine Is Saved!
The sim I wanted to rescue from oblivion is Miss Christine Tan. She was in labor when I last saved her household, so there was no opportunity to stop the pregnancy with the Insimenator's Reproductive Adjuster.
Christine Tan was in labor when I last saved the household.
It looked like Christine was doomed. If I could stop her pregnancy, I could then restart it with the current configuration of my game with hope that she could have a normal delivery; but since the labor animation had already started, there was no way to get her to use the Reproductive Adjuster before she attempted to deliver the baby.
Then Rose gave me the idea. Move her to a different household. It turned out even easier than that. I didn't need to use SimPE and didn't need to move her. All I had to do was delete her!
After deleting her, I saved the lot, exited, and re-entered. There was Christine, waiting by the mailbox. While the game was still paused, I had her spawn the Reproductive Adjuster and then used it to relieve her of her tragic, fatal pregnancy.
No longer officially pregnant, but still... erm... pregnant!
Now for the really fun part: Although she doesn't show as pregnant with either the Reproductive Adjuster or Danny's DMA Sims Teleporter, and although she has lived through a day in her life afterward without attempt to deliver her baby, and although she once again has the "Try For Baby" option in situations where she might have such an option, she still looks, dresses, and acts pregnant! She's still eating for two and her bladder isn't happy about that extra mass, and she's even still on maternity leave from work!
The one remaining question is whether she can have a normal pregnancy now. That's the next thing to test. If it works, I'll know how to rescue any other ladies whom I find with a Pre-Nightlife pregnancy. Some of my sims have been wandering around pregnant for years of real time, but if Christine comes through, I can still use the Reproductive Adjuster or Tombstone of Life & Death to restore them to their happily pregnant state without messing up any on-going relationships.