I see what you're saying, but I have always thought Betty was just frightened. The chick was added last to a flock of 3 other chicks when they were 4-5 weeks old, and was harassed by the others. Every time I go in the coop, Betty acts like what you see in the pics. She/he is always behind the others, or tries to duck and crawl under them.
Do you mean Jade? Because Betty's body language is bold upright and doesn't look like s/he is trying to duck anything.