I just checked her, found out it was one of our much older hens who would get into fights with her over food, she is almost 6 months, our older hen is around 1 1/2 years.
Okay, good you now know who the culprit is...
How many feeders so you have out?
Try blocking the sight lines between the feeders with solid objects... it can be anything from plastic tubs / leaning panels of wood / lawn chairs / etc. All sorts of stuff makes for good "run litter" but make sure it's placed in a safe way, and that a picked on hen can escape in at least two directions if the bully comes around.
What often happens is bully hens decide the victim should not eat and they run between the feeders shooing them from each one. To combat it you need to have more feeding locations and less sight between them so the bossy older hen will just focus on her own snacks for longer periods.
With juveniles in our flock and a cranky 5 year old bossy gal, we have 6 feeders out as spread as they can be... not all are visually blocked but enough are that even the most timid birds can access food.
We did similar with the water too... 3 separate water stations spread out.