The Dominant Step-Mother (2008)

Julia and Jonathan are spoiled rich kids living a pampered life in Beverly Hills. At least until their Dad re-marries. His new wife, Nyomi, takes it upon herself to discipline her unruly stepchildren. Julia and Jonathan think they can outsmart Nyomi, but soon realize they are up against someone who knows more about discipline than they ever will. Nyomi uses sibling rivalry to turn them against each other. Then Nyomi and Julia strip Jonathan of his clothes and his masculinity. They dress Jonathan as a pretty little girl. His soft feminine features rival the good looks of his sister. This results in the two stepdaughters competing with each other for the love and affection of the dominant Nyomi.