How big is the sofa bed in the living room? Would two teenaged girls be comfortable there, or should I let them use the bedroom and sleep on the sofa bed myself? Any other options?
You have the double sofa bed and the single sleeper chair at OKW so they can have a bed each and you have the King. Personally I wouldn't give up the king bedroom for anyone.
Since you will have people sleeping in the living room, I would request building 30 or higher. There's a second bathroom entrance through the laundry room. Otherwise they have to go all the way through the master bedroom to get to the bathroom.
You are going to love staying at a DVC resort. We bought into the DVC years ago and have enjoyed our stays ever since. When you see the size of the 1BR you are going to be amazed. How long is your stay going to be?
I would keep the king in the master to myself if I was you. Give one girl the queen sized sofa bed and the other the twin sized pull out chair. That way everyone gets their own bed, and you get a room to yourself away from the teens.