The problem ended up being that they had both registered last year with different user names. Forgotten of course. My wife had given me one incorrect user name and told me that my other daughter had never registered at all. I only found this out after going through the registration process several times and getting rejected. Tried to create new user names, went through the whole process, then was rejected again and told that the original profile needed to be used. eventually recovered the original user names, changed passwords, and registered them for the exams.
So, just another fun, last minute project delegated to me by the wife, after already working a 12 hour day.