OMG, I am so sorry. Your story mimics mine 100% except my step-daughter is now 13 and we have been putting up with this crap for 3 years now. I believe you are right to think her words are placed there by an adult, probably her mother, what child comes up with those things independently? our daughter said very similar things. The advice we have received is love her, give her parental boundaries, she will come out of it and realize the truth at some point, probably in her 20s. The child is likely suffering from Parent Alienation, a real thing, and very common. God help us all with this problem, and it is usually fathers who are affected. Apparently this is child abuse and in certain States and countries, illegal.