Primeras like her and the emperor have a very looooong life but they could die young if their powers weren't used 'properly'.
For example, if a primera wants to control an individual,the life span needed would be based on how strong the target would be. The stronger the target, the longer the life span would be needed to be sacrificed and there's a reason why it's like that and it would be revealed much later in the story.

Can someone explain to me about the life force theory when she use her power? I dont quite understand that part, like wdym if she used certain power than she aged 200+ years?? Or am i wrong?