Ok, I understand that you feel that it would be useless.
Have you tried using ancestry.com to find her?
Put the name, place where she lived after she was adopted, ( that is very often the area where she was born, especially if she was fostered) and an approximate birth year, you will be given up to a 10 year either way option. You will probably get several options come up. Next search each name in "other people's trees" and see if anything comes up, these trees are particularly useful. It takes time and there are lots of dead ends, but I have had success with several different people's trees. People on these Geneology sites are very helpful.
Good luck, I hope you are successful in the end.
Moderator comment: edited for content. Please do not suggest asking for look-ups from commercial sites. Most commercial sources have strict 'Terms of Use', which forbid publishing their data elsewhere, so asking for such look-ups is also asking people to ignore the 'Terms of Use'.
http://www.rootschat.com/help/posting_guide.php