I would say your overeacting a little bro..When I was a kid everywhere I went I got offered candy and never thought anything suspect of it...Halloween every year, think of all the kids eating anaymous candy from all over the place..Very rarely do you ever hear of kids having problems...The lady was just being nice and I don't think she was acting irresponsible in anyway..The way you raise your kids is your business though so I would be more angry at your kid she knows your rules..The lady has no clue about YOUR particular family rules...just my 2 cents
Later,