spin doctor in training

.02 take it for what it's worse but after working with kids for most of my life, you need to get her into counseling. You also need family counseling. I've seen many a case of a step dad losing his temper at a rebellious step-child, taking it to far and hitting/beating the child. When that happens then all hell breaks lose. Step dad is ALWAYS arrested and goes to jail, then Child Protection Services get involved, so your family is dealing with two different courts. Criminal and family, you have to take days off work several times a month.
Trust me please just go see a Family Counselor and talk it out.