Parenting Teenagers (12-18) Support Group
This community is focused on the joys, challenges and concerns faced by parents of teenagers (12 to 18 year olds). The major areas of child development include: physical development, perception and sensory development, communication and language development, cognitive development, emotional development and social development.
I suspect your kids want to make sure the step sister doesn't get the "get out of jail free" card because she is a step sister. They want to be sure it is all fair. I don't know how you feel about fairness between the kids. I think it is okay to let them know that you are working with the parents and will come up with a discipline that will be just and fair and they don't need to worry about it.
While it makes sense to have the same set of rules for all of your children (and this is the case with most things), sometimes it just doesn't apply. For example, when I was a teenager, the rules for me and my younger brother were not the same as they were for my older brother. My older brother had broken the rules and had more stringent rules enforced with him because of it. My younger brother and I stayed "in bounds" with the rules so we had more privelages in comparison.
My two girls (including the step-daughter) and my youngest son have more privelages than my teenage son right now because my teenage son has failed 7 classes in the past two quarters of school. He feels that I am being unfair in how I have dealt with is poor performance at school, however, he feels that he is within his rights to determine how to discipline his step-sister. My wife and I do not agree.
EverChanging - as far as bringing the hammer down, my son lost driving privelages to school the next day because of his refusal to do his homework. He did what he needed to last night so got that privelage back.