Lucy, who had, up until now, been hanging back, internally ravaged with hunger, wanted to quite literally growl at the one who now displayed the cross so freely. While she did not give into such an audible display, she was too young, too inexperienced and too hungry to prevent fangs starting to shift into place. Luckily, though, at least for now, they were not wholly visible.
Nevertheless, the lure of joining in physical confrontation proved too great and the vampiric brunette lunged at Fox. It simply would not do to merely stand by and allow another young woman to be attacked.
That she was hoping to 'accidentally' spill some actual blood in any resulting assault, was almost besides the point...