Hey HFA, I am divorced (2 years) so I thought I'd throw my two cents in.
My ex-husband actually found someone to date (I have not) and he has been dating her for about year now. Initially it was a shock to me to see him with someone else and it got to me start questioning, "What is wrong with me?" etc.
I was really pissed off at him once because he brought my daughter to an amusement park with her one day and never bothered to tell me ahead of time that he was doing that. In fact, he never told me much about her at all. It was totally disrespectful.
I think if you take it slow and gently ease into things it will make it easier on your daughter and ex-wife. Also, make sure to be open and honest and upfront about things. Just showing up at a reunion with her with no advanced warning is not a good idea, just like my ex threw me for a loop when he didn't tell me that my daughter would be spending a whole day with him and his girlfriend.
I guess just giving it some time, patience and plenty of open communication is a good idea to ease the family situation. You can't expect your daughter to be happy about this right now and try to concentrate on her point of view.
I have come to accept that my ex is now seeing someone else and it hurts a little less now than it did before. I feel for your ex-wife and daughter -- give them time and understanding.
Congrats on the 17 days.