Probably just her personality. Try more treats and other delicious offers, especially to her (try not to let her get crowded out by others) and avoid making any moves to grab/touch her. Just let her come to realize that you're not out to get her and she may warm up a bit. Maybe never to a level of being handled, but at least to the point where she won't scitz out and go nuts when you come around. It will probably take awhile since she's so shy, but be patient.
Our five are all the same age, raised together since day one, handled the same since day one, and are five ENTIRELY different birds. Our BR and dom are total shoulder/cuddle chickens. When you're out with them, they want to be with you and will often flying up onto my shoulder or my DHs (whomever's is available at the time, lol) and can be picked up and handled without any fuss 99% of the time. While out wellie and BA are 100% friendly and like being around us, too, neither care to be picked up. The wellie will fly onto your shoulder, but not as often at the dom or BR, and likes to sit on your feet. The BA will never do either of those things. The EE is just a weirdo. She will stay with you, doesn't mind you being around, but make one move to touch her and she jumps and bolts just out of reach with a BAWK, every time. She can be caught, but not easily. She will come for treats, but not pets or hugs. Once in a GREAT while, she will fly onto my shoulder and I can rub her back a little, but it has to be when SHE decides or you can forget it.
