Forensically, when a young girl suffers a gunshot wound to the chest, there are two potential pathways regarding how she loses consciousness:

Immediate Loss of Consciousness:
Traumatic shock—caused by massive systemic damage, sudden neurological reaction, or a severe drop in blood pressure—can render the victim instantly unconscious (as depicted in the released version >>23829).

Delayed Loss of Consciousness:
If loss of consciousness occurs due to cardiac arrest, it typically takes anywhere from several seconds for brain tissue to deplete its oxygen supply and shut down after blood flow ceases (as seen in this scrapped version).