Something I've found to work is to act dominate. If she's screaming or acting bratty show no attention or affection, just ignore her, don't look at her, and continue what your doing. Also don't get her what she wants until she starts acting nicely. A lot of times kids throw tantrums for attention. Yelling and screaming shows attention, acting like she's not there is not showing attention.
Annie:
Being an alpha is not about being nice or nasty...FMS has some good advise....set standards, ignore bad stuff....it will go away....my two cents....