She probably got it hung in fencing or a feeder, unless you saw it happen...you just don't know. I've had a few chip and crack their beaks, sometimes it happens, usually they are fine without my help.
It doesn't look "fresh". Is she eating/drinking o.k.?
Normally I'm inclined to leave something like this alone, but you could
lightly file the end to smooth and round it if it looks like it's going to split.
Is it torn near the nostrils as well? Some people do attempt a repair if it's torn too, you can see how in the following link. If you search youtube, you can find more videos too.
https://the-chicken-chick.com/repairing-chickens-broken-beak/
View attachment 1817452