Fr. Z just put up an article responding to a question about a Catholic marriage being valid with a Protestant minister "officiating." His reply might be of particular interest to you ladies b/c he goes through a few different scenarios and says what is and isn't valid. CLICKY
The choice of words matters: Often times we'll hear of someone who says something like, "oh our priest is co-officiating (or whatever) with another denomination." Well, maybe she just doesn't know what she's talking about, since the main thing that matters for it to be a valid marriage is that the *vows* are received by the Catholic minister.