Brrrrrr

Just so I know proper Trick or Treat etiquette....is it okay to wear a jacket over top of your Snow White costume if it is freezing cold outside on Halloween?  Also, on a related etiquette note, is it totally cool to tell your daughter "Oh, I'm sorry, baby, that is only for grown-ups" any time she gets candy you want to eat? I'm not saying either of these is definitely going to happen. I just like knowing my options.