HI GUYS, LET ME START BY SAYING I'M NEW TO THIS BOARD.
Look at the other listening post in this section.
Try to focus on what she is doing right and praise her. You want to reinforce the good behavior. I'm not saying you need to completely ignore when she does something rude or mean but you want to give her less attention for those types of behavior. Kids want attention and they really don't care if it is for doing something good or something bad. They want you to pay attention to them.
If your husband continues to talk about her that way he is not helping matters. In fact I think he is contributing to the situation and making it last longer and harder to help her stop doing the things she shouldn't be doing.
The comments that your husband is making are not right. Children live up to their labels. It's best that he stops before he damages her self esteem. I believe your expectations for her are a little high. This sounds like normal 4 year old behavior to me and trust me.. as a nanny I have seen much worse. Persistence is the key and as a parent of a 3 1/2 year old I slip because its really hard to stick to your guns ALL of the time. My best advice to anyone with a toddler turned defiant with a new baby in the house is to make sure they have playtime with friends their age. Also applaud all of her positive behavior and make sure that she understands what "bad behavior" is. I usually go for taking away privileges before time outs with children this age. If they have a favorite toy or blanket I will put it up and set a timer and if their behavior is changed by the time it goes off they can have it back. If they are still screaming after the timer goes off its time for them to have alone time in another room away from others for one minute per year. I will then go hug them and tell them why they were punished and ask for an apology. By then they usually are ready for some loving and to behave.
I would also suggest speaking with her doctor about possible food allergies which can have a big part in this kind of behavior but I honestly think shes a sweet and normal 4 year old =)
Good luck I hope everything works out for you!