Did you call the police? If you didn't, it's not too late to do so. You may have information they can use, (if in fact this turns out to have been a criminal ploy).
I called the cops and reported it right after she left. I was more curious if anyone else has experienced this as of late
Someone posted about this warning a couple of weeks ago, about individuals approaching homes and posing as legitimate emergency or utility workers
http://southorange.org/notices.asp?guid=c98ddf94
Someone stopped by my house yesterday in Maplewood claiming that there had been an cable outage in the area, but they had no uniform or name ID or even company vehicle (they were on foot).