How did you handle a teen's back talking mouth ?

Just be all nonchalant about it; getting emotional in responses only adds more fuel to the fire- you have to be the one "cooling down the fire" in that scenario. Don't use the word "Why"(nobody likes explaining themselves when they are moody); instead sneak questions in easy to answer form- "do you...", "are you...", "is it because you...". Also, don't tell them to settle or calm down, it has the opposite effect. If all of that doesn't work, surprise her with your own off the wall comment(something really bad that'd she'd only expect to hear from someone her age or a bit older)- she'l be so shocked of what you said she won't know what to say. Just make sure to not use anything personal here, just something really dirty/bad, that could generally apply to anyone.

yeah my teens would have been back slap.. and wouldnt be allow to do nothing at all. then they would loose all rights to have a cell, games, phone calls, and going out. my kids learned they dont talk back to me or my wife, and if they are ever dumb enough to raise their hands at once of us, well my son found out once when he picked himself up off the floor he looked at me said boy i that was dumb