DRAMA - Where did I go wrong and how do you fix it?

DRAMA - our hectic home was full of it this weekend.  We can normally escape most of it by talking about it and how each of us can make better choices to avoid or defuse it.  But this weekend, I found out that apparently I have officially become the "strict" parent.  The mean mom who is over protective and too involved in her young daughters life.  The funny thing is, I am strict, especially when it comes to Drama and how it effects our family and those around us.  I am strict when it comes to making choices and the consequences that go with the choice and path you choose to take.  Personal responsibility is key in our household.  I don't know when I become "this" mom, but someday she will appreciate my rules - maybe?  We spent a great weekend out at the lake with some friends and then my tween age daughter (Madz) was going to have a sleepover with a girl I am not to sure how I feel about.  I believe that more time is required to see how this one operates and behaves with us in multiple situations.  I just do not know if I can take to much more of this "discovery" period.  The afternoon was pleasant and the lake was amazing.  Water always calms me down and a tan always makes you look better - that's my version of win win!  The issue started when I overheard my precious little angel talking about another friend of hers who was not there.  Do they ever learn?  I immediately called her aside to defuse the situation, assess the damage that had been done and discuss with her what was going on.  She knew immediately what choice she had made and that consequences were about to hit the fan.  She made a conscious choice to talk about a friend who was not there to defend herself or to hear what was said.  I asked her to put herself in the friends shoes and what if she found out that one of the other girls was talking about her; she would have been devastated and angry. I think I was actually in shock.  I honestly felt like we had openly discussed this Drama issue over and over and Madz knew how to make the better choice.  I must say it hurts to discover that you are delusional and really not in touch with your changing child.  I have to admit that I felt like a failure at this point.  What could I have done different and how do I handle this issue from this point on.  That is where my blog friends come in handy.  How would you handle this situation?  I am open to the criticism, critiques, and help.  My mantra is "it takes a village to raise a child, and I need all the villagers I can get".  Maybe a DRAMA free zone should be drawn up, like a peace treaty.  Food for thought...good food for thought!  What is your drama free zone?