K.W.
I really like all the ideas, especially about getting a baby for your daughter to "care" for and having her help with caring for the new baby. I have one suggestion to add: have it be a "gift" from him to her--that worked for me. But otherwise I found I could never leave my infant alone with the older kids at that age. You just have to carry them with you and if you can't, then have a seat or swing or something to set them in. Floor time always has to be supervised once you have more than one child. I even had a seat set up in the bathroom (since that is where I usually was when the torturing started) so that I just took the baby with me, locked the bathroom door and set him down until I was finished with showering or whatever. If your daughter freaks out and starts banging on the door don't be surprised. Then you'll know that before you go in there you must get her busy with PBS or in her crib with a book. Most importantly, just hang in there and make sure your daughter knows you love her and that having a baby is a good thing for her too. You have to change your approach to parenting more than one child--just roll with it.