Alright, this is about as far as you would be able to trim, notice how you are looking to only trim the clear-ish looking ends of her beak. She’s got quite a bit, but it’s not too bad considering her age. Definitely take it slow and easy your first time. Don’t worry too much about trimming it all back, especially not until you get more experienced and get better at finding that clearer part that can be trimmed off. The black represents the quick, and the purple is the part that you
could safely trim off, but even I wouldn’t go that far. What I drew is not perfect, so definitely double check on your hen to make sure.
This is as far as I would go-
I would leave her lower beak longer so she is still able to scoop the feed in, but it looks like the sides need trimmed.
If you are worried, I would just start with this-
Remember to go slow and just do as much as you feel comfortable with. Take it little bits at a time. Do a bit, wait a few days, and come back and do a bit more, it really won’t make a difference. It’s honestly best to trim it slowly and gradually (like doing it small bits at a time every few days) as it allows the hen to gradually get used to it. The important thing is that you just go slow and get the feel for it before diving in and doing something you’ll regret.
Hope that helps! Good luck! Keep us updated!