Not an atty, but yes, if KK lies about anything or does not follow the judges orders (i.e. she talks to the press), the deal is off the table. That's why they won't sentence her until after the PF trial. If PF comes out with something that contradicts what KK says or implicates her further in the murder, and KK hasn't already fully informed the court, she will lose the deal. There's every possibility as this progresses that there may be other charges if she had more to do with this than she has told the courts. My guess is, once PF realizes KK is being completely transparent, he'll turn on her and we'll really hear what happened.