Answer:
The narrator is saying that they used to think the world was some magical place with no flaws, and then they realized it was otherwise.
"Or would I leave her be naïve, to keep having fun?" The narrator is going back and forth between leaving themselves innocent, so that they can enjoy it while it lasts.
The author is considering this because "I would give up everything I have, to view life through her eyes again." As a child, she was innocent, and loved the world, and is wistful to feel the same way again.
Hope this helps :)
Stay Cold,
Brook