Crin does not have that bug listed where toddlers wont age up. This bug is only specific to female sims. I had triplets only the boy would age up but not the girls . Their mother was the sim I moved out while pregnant and that is where the whole bug started. My active household has a baby girl after that would not age I deleted her. Tried for another baby again a girl would not age up. This is when I deleted all the baby girl tollders in my town. Moved the sims that were causing the problem. The glitch attaches to the house, not just the sims. Once I moved tham out of that house that lot became corrupt. Could not move another family in that house so I bulldozed it. Problem resolved. My active household had more girls and they aged up just fine.