Whenever you leave one household to play another, the game starts it's own story progression. Your sims that you left in the other house might get jobs, get married, move, and even have children while your away playing another household. The ages pan thing could be 2 things I think. Either she is of the occult, a vampire or fairy. Or my other guess is that she got a job at the fairgrounds she got a crazy long lifespan because she became one of those townie sims that works somewhere. Hope that helps!
Sent from my iPhone using Tapatalk