Okay, now about what you, were asking...
It is hard to say, but let me go with what I am feeling from this and also how your wife would be thinking on this point. She, feels bad for what she has done to you, she knows she has been in the wrong and done wrong by cheating on you. Which she has told you this as well, as just the part of her not wanting to divorce you. Which is really good for you.
She, has also been thinking about your good times
you two have had together throughout the years... She, also feels bad for leaving the boy behind and also walking out on you on top of it. I am going to tell you, this much as well, "Do not move on- she will be back into your life" It may not be tonight but it will be within the next month. She will act odd towards you tonight as well; while you people out as a family. Just be happy you guys are all out together and it will be a good night for you... (Trust me I am right on this-)