Thanks for the responses everyone! Dawn used to not try anything other than her seed diet, but it seems like once I finally got her to try something different (a piece of lettuce), she now will try anything I put in front of her. I enjoy offering her a lot of variety now.

Here she is attacking her celery earlier today while ignoring the lettuce:



She also kept climbing one of her ladders and munching on millet spray. It was hard to tell which she enjoyed more.