One of my girls seems to have a frequently poopy booty. She hasn’t had any health issues yet. Is this normal? Should I trim the feathers? Also newbie question, do you bathe chickens in winter? She is 8.5 months old, gold lace Wyandotte.
Take a good look to make sure it's not more than just the bit showing in the pic.
Make sure her vent is clear.
Fluffy butted birds often have this happen, mostly it's not a problem, they will preen it off.
If it gets worse, yes trimming the feathers(to about 1/2" from skin) can help.