Toddler rapidly aging up

My toddler keeps rapidly aging up to an adult every time I load the game. I have turned off auto-aging and tried repairing the game multiple times but it still happens. As soon as the game loads she immediately ages up and then keeps aging up again and again. I have to exit without saving to get her back to a toddler. Really frustrating. 

I play on PC, don't have any mods and only have two expansion packs. This is the first time I have run into this issue and I've tried everything I can think of to repair it but it hasn't helped.