Sometimes, chickens develop hard growths or scabs on their beak if the beak has been injured. I know that when my birds get a injury on their beak (for example, when they fight with another bird through wire and the base of their beak rubs again the wire), it often develops into a lump or scab. One of my birds in particular got a small scratch on her beak that turned into a hard lump. It went away in a few weeks. Your bird is probably fine-- if she continues to rub the beak on something (wire fencing, etc), it may not go away for a while, but should eventually.
Oh, thank you. We recently had a disaster with a bobcat killing my lavender orpingtons sister, and there were some minor injuries, so this is probably one of those. All is well now after building an enclosed hen run like fort knox. Sad, but our fault, and this is wildlife.