I think part of our trouble is that we didn't bring the girls together gradually enough. We did try taking clothing back and forth and we had a blanket we used this way and each girl would sleep on it while it was at her house. Then we brought my hubby-to-be's girl over here in her carrier and introduced them that way before having her spend time here out of her carrier. And of course, we can't roll back time and do it again.
There is, of course, the possibility that they wouldn't have gotten along anyway. Someone told us they either will or they won't. I guess since things have calmed down as much as they have I'll be grateful for that. At least we don't have daily sessions of hair-raising, someone-sounds-like-she's-dying anymore.