I agree. She was really alone, FWIW. I'm sure they were all instructed before leaving home and when they got there to look out for one another - moreso with lacing drinks w/drugs. But when in the midst of fun/sun, etc - all precautions may have seemed unnecessary.
Not blaming any of them - they are all the same age and the same mindset. There is something about "street smarts" that is missing. I can't imagine how some of them are feeling now, mostly her cousin.
I agree and the, "What If's" are constantly pounding in their heads. NSNR