Thanks.
Being an Alabama native, I would've been able to answer that one. I remember that from her biography.
I couldn't figure out why Rachel Carson would be a good guess in lieu of Helen Keller.
I would venture to guess two reasons.
1. All three are kids who were indoctrinated from their earilest years the see Carson (who is responsible for more deaths than Hitler and Stalin combined) as some sort of eco hero.
2. The show was recorded in Pittsburgh, which was Carson's birthplace.