So, I had my simself steal away Eliza but ever since she's remained a young adult. My simself has long since passed on but she's not aging. Sim npcs are aging and so are Eliza's three boys. It's only her that is not. Never even seen any notice that her birthday is approaching either. Very confused by this.

Do you have the Vamp. pack. If so maybe she is a vampire??? Other then that you might have a bad save or bad Mod. Never heard of this. Good luck

I figured it out. Apparently it was decided for Sims not to age while pregnant. :/ Since she had three pregnancies just about one right after the other...well...anyway I aged her to adult with Master Controller and found a mod that fixes this. All is well.

Well she was a busy girl, glad it wasn't a real bug