Sometimes,the smallest,goes off on her own.
I have to lift her up at night,to put her to bed,she's tame,and allows me to lift her gently. Could she be bullied,or just independent? They are all laying
After struggling to integrate my new ducklings into an existing broody flock I can comment on signs of bullying.
If you see plucked spots on back, neck/shoulders or wing edges then she may be bullied.
If you see plucked spots on chest you may be seeing signs that a clock mate is trying to "gently" show/teach the hen something.
I have a few independent hens in my original flock. Most of the time they're all together but if one is thirsty or wants to swim or go luck for bugs in the leaf litter she'll go by herself to do that thing and keep doing that thing until the others join her or she decides to rejoin the others.