Need to? Nope. But I would highly recommend it. Coming from someone who was a reapplicant myself - clearly whatever she did this year didn't work. I would strongly suggest rewriting, and exploring completely different subjects for at least some if not all. I firmly believe it's what got me in my second time around.
I'd have her contact admissions to see what they think she needs to work on. They will go over what they saw, how it fell short and what parts to improve. CGA loves reapplicants, and nothing says I Really Want The Coast Guard like reapplying, but she will need to make some material improvements in her app to match that resolve if she wants a different outcome. The director of admissions, Capt Fredie, got in on his third try so keep at it. Good luck.