I know what you are talking about and it sucks that it feels like a game and it's not genuine to do that. You can do whatever you feel you need to do. Just because you feel like doing it this one day, you may regret it later. But if you feel like you need to this for yourself and if you aren't worried about what it will do to your guys relationship, I say do it.
I've been in that position and let emotion guide my judgement and I've found myself doing regretable damage. The fact that you are contemplating what to say to her might be the effect she wanted. I don't see the harm in saying "You too" but I wouldn't agonize over it. It might even make it seem like you don't care. Like I said, it's too soon for a difference and anything that happens now is going to have a miniscule effect. If you would like future reconciliation as an option in the future though, going back into talking about your relationship with her is probably going to bring you back to the beginning of all your progress. I know you have made some serious strides but this could mess you up mentally.
The only way you can get a genuine answer is if she wants to talk about it and she wants to come to you to let you know. There is nothing else you can really do.