Stating something like that also goes back to putting focus on something you may not want to add to. By drawing your attention to the situation you may add to it therefore put more pressure on it. Which is counter productive. You don't always have to directly aknowledge everything someone says. Don Draper from the show Madmen said, "If you don't like what's being said, change the conversation." So my suggestion is to behave that her recent confession never happened and escalate as planned regardless. If she does bring it up again you could try behaving like she is being weird for bringing it up. But again use your best judgement.