Y.K.
I really think at this age they understand what they are doing and how affective it is to you and your husband. First I would like to know who watches your child while you are at work? I'm wondering if she is allowed to act like this with them and what do they do when she bucks the system. It sounds to me that your daughter is acting out to get your attention and sometimes bad behavior gets that. Having another child would help not only you but it would make her feel like she has to show the baby how to be good. What I use to do with my children was put them on time out try this. If she tries to leave, screams, kicks, cries, etc. walk away and let her have her melt down but leave her on her time out area for 5 min maybe longer. Then talk to her by going down to her level and let her know that what she did was wrong and make her understand by asking her. Trust me she will come around I have have four boy's it will stop. I don't believe in terrible two's there terrible if we allow it to be. Good luck!