That's what was found on scene, not what she ingested. 16.9 grams is over half an ounce, a full tablespoon. She probably ingested a pinch or a filled capsule--I'd guess 1/20th or 1/100th of the leftover amount.
Right. That is what was found. It was enough for them to determine if it was marijuana - or not. Unless it was laced. But, 16 grams of pot was enough to see, yet they called it an ‘unknown narcotic’.