Facebook – How to search for people given certain details about them

I was told that it's Facebook policy to not allow the changing of URLs after they have been changed. I was told that she should delete and recreate her account.

Yes, even if you have received a friend request from her, you may not be able to Send her a message depending on her privacy settings.

What you can do here is accept her friend request; then place her under the list called, "Restricted" and then send her a message. Later you can remove her from your friend list.

Or, if you are sure that you do not know her (or anybody with that Nigerian Name); you can cancel her friend request.