There's no real graceful way to say, "Dial it back about two notches. You won. It's ok. Calm the fuck down!"
She probably won't even be able to. That's assuming that she knows what you're even talking about. It is entirely possible that she justwon't get it. I only say it because I've known a few girls, and they were smart girls, but when it came to something like this it's like... you might as well not even be saying anything in english. It's not that they play dumb. It's that it's something so basic to a personality that you might as well be telling them they need to breathe less for all the sense it's going to make. If she's one of those... well, I mean. It'll take time. And if you tough it out you'll probably wind up missing it. "Hey, remember when you used to be insane? What ever happened to that. It was kinda nice, now that I think about it."
Oh. Play that Grateful Dead song over and over and over and over again for a few days. "You're my woman now, make yourself easy." That might work.