So the flower girl for our wedding is going to be my FI's daughter. She will be about 6 1/2 years old at the time of our wedding next spring and has been in multiple friends' weddings already. Quick background story - he was married before, the ex ran around and cheated on him several times after she had pressured him into having a child with her (the reason it was several times was because he gave her two chances since they had a daughter together and he was trying to make it work for their daughter, and she did it a third time and he finally got hard proof of her cheating and told her to get out), she always tries to pawn their daughter off on us cause she doesn't want to watch her or deal with her (which we think is fine because the more we get his daughter the more we know she is being taken care of), and she (the ex) is a crazy b---- in general to the point where even her own family doesn't get along with her half the time. I assure you if you all could meet her in person, you would wonder how someone hasn't locked her up in a hospital yet. She's that bad. So I guess here is my question. First of all, do I need to write out an invite just for his daughter? Is that sort of required proper etiquette to send an invite to the flower girl? And secondly, do I need to mail it or could I just give it to her one time when we/his family have her? The reason I am asking is because I honestly wouldn't put it past his ex to try and wedding crash, so I really would rather not give her any details that I don't have to. Neither she nor any of her family is being invited to the wedding. She is always full of drama and trying to start b.s. stuff with him and his family, and she has admitted to people in his family that she is super jealous of me and she knows she screwed up when she cheated on him. Needless to say we try to avoid drama where possible. Any advice on how to tactfully handle this, especially from anyone who has had to deal with a crazy ex, would be appreciated.