"For––for fuck's sake," muttered Mattie, her hands shaking as she bent and picked the crowbar back off. It'd been a stupid decision to throw it down. The noise had probably alerted this douchebag's zombified sister as to their location. She could toss it later. Preferably at him (yeet). For now, it seemed, there was possibly an undead kid to deal with, and after that, Mattie figured it best to leave. 

Logically. The pity eating at her meant it would be harder in practice.

"Okay," she said, putting her free hand briefly to her forehead. "I'll look for her and you can burn this corpse."