[Unfortunately for her, Veronica isn't paying attention. She's too caught up in her own feelings & fears. Even before being dragged to prison, she had been struggling between the person she'd grown to become and the person she'd been as a resident of Neptune, a person she'd thought she'd escaped and had come to almost embrace. Yet while she accepts the part of her that she will always want it dark, gritty, hard, complicated, unpleasant, there are a lot of parts of her high school self that she never wants to be again.
So no, she has no idea Nathan's there, or that she presents a perfect target for him as she leans against a railing and stares out at a park.]