Lump on or near clav
It would be common for a 7yo to have a crack in the clavicle from simple trauma and a lump to form over the bony area.
Such cracks build a onion like healing knob that disappears over months to years & requires no special rx. That bone is one of the most often broken by humans. A lymph node can also be a lump near a clavicle & seldom a pbm in kids.None of what u say brings thoughts of bad news.