Well, there is always Buzzle, but it tends to be a little more generic and less wedding focused, particularly since most of the people who left were already married and had moved on in their life (sort of like you seem to have, com weddings to families and babies).
I can't think of another more active wedding forum unfortunately. WeddingWire and The Knot have forums, I believe, but i can't vouch for them. I think the hope around here is that some fresh faces will find their way here and revitalize the community. I would encourage you to encourage her to come on over and join up.