You should worry about your case,maybe speak to a lawyer,in case they try and bring more chargers against you. Endangering the welfare of a child (it's a long shot about you never know),maybe they could add some other drug realted charge or something else.I would be concered about the police bothering me for info or other crap if i was you..Are they only charging you with one thing still? In new york 17 year old is an adult. The da prob going what the police report said.

If all your charged w. is Unlawful Possession of Marijuanna,it should just be a volation. Maybe there a lawyer who has a free ph consulation or somewhere,where you can ask him question.When you go to court,see if you can ask a legal aid a few questions. The fact that the da mailed you letter could mean they have intrest in the case b.c it involded a group of ppl.The da already knows the law,mailing you the letter is legal.