Why does being a good parent make me feel bad?

For the most part, I had a good day with Jenna. She had instigated an episode with Alyssa in which a hanger was thrown by Jenna at Alyssa. When Alyssa tries to defend herself, Jenna threatens to come tell. I know that is not the whole story when Jenna tells since Alyssa is 16, and well...she doesn't throw hangers or hit Jenna out of anger, even though if someone threw a hanger at me, I might be highly inclined to retaliate. After wading through all that and talking to Jenna about it, we went on with our day..having lunch with friends, renting a movie, and hanging out at home. We grabbed a bite to eat for supper and went shopping at Big Lots.

I guess I should mention saying that we've had a hard time with Jenna being whiny and having a sassy attitude. It's been going on for quite some time and we aren't having much luck in breaking that bad habit.

So tonight, at the register, she wanted candy and since she had behaved well in the store, I said yes. Right as I was paying the cashier, I said something to Jenna. The sassy and the whiny just popped right out of her. I was quite embarassed and irritated at the way my child has just talked to me. So quite calmly, I handed the candy to the cashier and said, "Have a treat on me" since I had already paid for it. Then I took Jenna's hand and out the store we went.

I can honestly say that I think I got her attention with leaving her candy at the store. I explained to her that I wasn't going to buy her candy if she was talking like that, etc, etc. She cried all the way home and honestly, I felt miserable. This is not the first disciplinary action for this behavior, but I think it was the roughest. It would have been so much easier to just give her the candy, but I just can't have her continue on like this, kwim? I sure hope this will help her learn the lesson.