Large lump on 8 week adopted chick - rarely stands

[sugarhousehens]

We just adopted two chicks that were given to people that had no intention of keeping them. We got them all washed up back on good diet and have them in a separate cage in our coop so the other hens can adjust to them. When I was cleaning them this morning I noticed that this chick has a large lump just below her collar (see pics). She also prefers to sit 80% of the time and has a pretty rank smell....wondering if this is normal or if the lump has something to do with her lethargic behavior. Not sure on the breed either. The chick is mostly white when not wet..

Any help would be greatly appreciated.