Hey there abbysdad just checking in on you. You do need to set your boundaries when it comes to her having her "friend" over. She may think that it does not have an effect, but believe me it does. You should tell her calmly that she should not introduce her to any other friends until everything is final.
And you need to be strong. This is the tougest thing I have ever been through. You just have to tell yourself everyday that this is going to be a great day and think of ways that you can improve YOUR and yr daughters lives. We all know that we can not do anything about our spouses so why try. You will just drive yourself crazy with the questions about what she is doing etc...
Everyone will backslide occasionally, but when it happens think of ways to fix it. Do not let her bait you into an argument of any sort, and act "as if" to whatever she says when she trys to hurt you. Pull out all the 180's and blow her socks off with the new you attitude.
You can do it!! Hang in there buddy we are all here to support you!