R.R.
I'd advise taking the crib down completely and putting it away, even if you have to set it back up again in December. Reason being you don't want your daughter to associate her move to the toddler bed with the new baby and develop resentment or animosity towards her new sibling. It takes a couple of months for them to fully adjust to the bed so you want the transition to happen fairly quickly at this point.
Put a baby gate in her doorway (I had to stack two for my climber) so you can still hear her but she can't wander out of her room, and have a nightlight in her room to help her relax, I recommend the ones by Cloud B to everyone, they project constellations on the ceiling for 45 minutes:
http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3...