Trick or Treat

Right now there are 3 small people in our living room watching It's the Great Pumpkin,Charlie Brown and H and I are trying to stay awake til their parents come back from their Halloween party.
Here's the question: who are these two? In our front hall, upon delivering the boys and Tatum.....Son #2 is 6'7" and this suit is BIG -I wonder who else could possibly wear it (-maybe it was on sale?) and I wonder who can guess who d-i-l is? I happen to have read this book or I wouldn't have any idea.. The pin on her vest is a clue.... :-)