Thanks for the quick reply! I don't have any roosters, and she isn't even laying eggs yet so the clutch of chicks seems unlikely
They got out via my mistake, somehow the door wasn't locked tightly so they were able to get out, but you're right, it probably happened early this morning.
They don't free range a lot, sometimes if I'm around to watch them I will let them free range a little, but mostly they are in the run all day and then in the coop at night.
I found one feather outside their run area, but no other signs that would indicate an attack, and if they were in a group, the other two definitely look perfectly fine.
I'm not 100% sure what predators I have in this area, and I'm really quite new to owning chickens--I've never seen any potential predators in my backyard or neighborhood, but I've seen foxes other places in my town and I live next to a small strip of forest that could house other animals I've not seen yet.
Thanks again for your help, I will let you know what happens! For now I left some food and water out, hopefully if she is okay she will get hungry or thirsty and come back!