Solved
My Sim Won't Age Up
I have a few sims that this is a problem with and they're all twins. They're stuck being a toddler and they're all the older half of their set of twins. These set of twins have been girl-girl twins t...
Sounds like the Sim is corrupted.
You might find some solutions going through this link: http://answers.ea.com/t5/The-Sims-3/FAQ-Game-Corruption/m-p/968290/
A mod like errorTrap could help to unbug her.
