Help? How long do NPC related to your household stay?

Thats the thing I don’t want her to move out, I want to keep her, but in the previous versions of the game I know you had a limited amount of time before you either had to promote thrm to playable or move them out. Thats what I want o avoid. I want to,know so if I have little time left, I will just rush through thr last level of the hobby of the oldest sim (i already have the option to do it but haven’t done so because I want to finish her hobby first)