Well, the words you use talk about her discovering fears and things that make her scared and sleep not feeling like a safe, comfortable place/time for her. So, perhaps she's starting to experience fear (in a way that babies and young kids don't until a certain age, which is around this time) and beginning to have scary dreams.
Honestly, my daughter is going through something similar, though different in many ways because she's never slept throught the night, or come close to it. But, for me, I'm treading very lightly on forcing her to be alone with her fears, even though she can't vocalize them or talk about them. I just don't think it's going to achieve our goals or do anything helpful to her.
But that's me, and I'm not one for CIO anyway, so take my advice with that in mind.