Could there have been a welcome wagon event about to occur in her new Chestnut Ridge neighborhood when you saved and exited?
There is a bug like that reported, that results in failure to load game.
https://answers.ea.com/t5/Bug-Reports/OPEN-Error-Code-123-4a01697a-Welcome-Wagon-LE/m-p/12829712
Here's the posted solution-- I feel like it's more of a workaround, but it seems to work
I just managed to replicate this error on a new save myself, and it seems to specifically be an issue with the PreWelcomeWagon situation (which is the situation that spawns in neighbor sims prior to the welcome wagon event starting); if you save the game while this situation is in effect (before the welcome wagon event itself starts), you will get this error when attempting to reload the lot. However, I've found that you can load into a different household, then switch back to the original one and it should load, as the situation doesn't get saved when you switch between households. This error also seems to occur with certain welcome wagon type events you may get occasionally in Sulani (such as the Extra Food event); but again, it's only if the game is saved right before the event starts. If the event has already started, the error won't occur from what I've found.
