Leslie Jackson, 24, of Aberdeen, Md., was charged with aggravated assault with a deadly weapon.
Reports say Jackson was arguing with other patrons at Kings Lounge, 4864 Davis Blvd., as the bar was getting ready to close.
The bartender asked Jackson to leave, which she did but not before threatening to return with a gun.
Jackson returned to the bar a short while later and began arguing with a male patron, reports said. During the argument she pulled a handgun from her waistband and pointed it at the man, reports said.
Jackson left the bar, reports said. Deputies located her a short while later at a residence on Cape Sable Drive in East Naples.