Zack is one of a kind, but so are Angeal, Genesis and Sephiroth. She wishes, genuinely, that she could do more for them and it bothers her that Angeal feels any responsibility for events that happened after his death. Even the greatest soldier on the planet deserves a rest!

But it's not like she has rested either.

"He is the reason I entered the Lifestream." she reveals softly, "Cloud tried to stop it. This is...our fate."