It does, however, raise the risk of the episodic plot. "Of simple Plots and actions the episodic are the worst. I call a Plot episodic when there is neither probability nor necessity in the sequence of episodes." -- and when it was diagnosed as a problem as far back as Aristotle it probably really is a problem.
Well, the villainess of the story has a distance attack, and it's integral to the climax, so it needs foreshadowing anyway, but the question does arise whether show it from her POV. Which has its charms -- dramatic irony and all that -- but for this story, I walk about it, poke it with a ten-foot pole, and am leaning toward "No." She'll have to reveal too much info if she gets the POV, perhaps, or maybe she's just too dull, but -- no. (Thus far.)
Alternatively, there could be more clues. They would clue in the reader at the same time as the characters, but then, they have to figure out what she's put together before the story ends, so it's best to get started. They will get a thorough and unequivocal clue before the end, but foreshadowing is nice.