Did she get a vac within a week or so? Sounds more like a fatty mass. But I would have the vet take a look. With boxers, I wouldn't mess around with any lumps or bumps.
LISA ~ Lily LaRue - 4/07 boxer; Buster McDoogle - adptd 6/07 Vizsla/Besenji mix; Annabella Kanicki - 5/08-7/09 staffy; Mr. Smiley - 4/10 Boxer/pibble mix; Fozzy Bear - 5/10 Red Heeler/pibble mix