They use up a lot during the transition when the plant stretches and starts working on flowering. I didn't see any curling in your first 2 pics, did notice minor tip burn now that I paid more attention though. Nitrogen thing starts from the bottom and slowly works it's way up. No intravenal discoloration, just plain gradual yellowing.
I didn't mean to say you should feed more nitrogen, just what's happening. Flowering is well under way, she should be just fine