I'm sure somebody will post it here even though they shouldn't. There are several other pieces of information we would need to hunt down this person. However, not many Realtors will help you with this as we are not sure of your motive. There's several liability issues here should the meeting go sour.
There are many tools you can use to reconnect. How do you know Jean? There is the white pages and Google for general connections and information. Tax Records are public knowledge, so if you know where she lived you can look up those areas. If you went to school or work together you can check out the social networking groups, like facebook and myspace. You'd be surprised how many old colleagues and classmates I find on these sites. Many of them with large families now!
Last resort is to hire a P.I. Sounds kind of like an 80's TV show, but they could probably find Jean in an hour or two.
Great answer Joshua!
Too add to the first answer, you can also go to http://www.usa-people-search.com. For a small fee, they can find someone for you. Another good website is http://www.Public-records-now.com
Good luck Helene!