Whitecat,
I'm told she did, but I don't have any direct knowledge. I live one town over from Haddonfield, but I see a lot of track and know some area coaches and officials. From the meets I saw, it was clear early on that she would be a big-time recruit. Her father was a runner for Paul VI which was a high level program in those days. One of the guys I worked with knew the family and sometimes ran with her father. Erin was pretty well-known even in middle school.
I also saw Carl Lewis, Dennis Mitchell, and a bunch of others from this area before they were nationally known.