Glenda, I know how you feel about not wanting to put it off, because there are times when you will want to have BM days and need to do stuff with them. I also know that my BM's were very excited to be on our website, in fact one even sent me a beter picture of herself because she hated the one I had...anyway with that being said, because of what she has recently done, I would call her and tell her "you know I have been thinking and I didn't think this would make a difference but because you lied about James, he and I don't feel comfortable with you standing up for us, its just an akward situation and need to do some re assignments anyway because of the DW. Of course we would still love for you to be in attendance. I hope you can understand how uncomfortable that would be"
otherwise, what Kate said is really great too...I would personally not tell her this at the other wedding, because if she can lie like that about your FI what kind of scene is she going to make, and you wouldn't want to ruin your other friends day with drama. You also might want to give your other friend a heads up so you don't wind up sitting at the same table as this girl at the wedding. That would be really weird.