Officers responding to noise complaints discovered the intoxicated teens.
Police say beer and the caffeinated malt liquor known as "Four Loko" were offered to fourteen and fifteen year-old children.
"We have numerous witnesses who were there that will say that this woman facilitated and encouraged drinking on her property," said Suffolk Police Lieutenant, John Cahill.
One of those witnesses, police say, was a fourteen year-old girl who was hospitalized for alcohol poisoning.
McKinney's lawyer insists the party spilled over onto a large field behind her home.
McKinney is charged with endangering the welfare of a child. She has been released on bail and is set to be arraigned in Central Islip in November.