I found my bmom 12 years ago. There are a lot of adoption registries on the internet. I filled in my information in 3 of them, and I had a phone call the next day. She was looking for me, too, or this wouldn't have happened so quickly, and maybe not at all.
Many register with ALMA, some mothers leave a letter in the file at the placement agency to be given to the child if he/she searches after age 18. I would try both of these if I were you.
If she's 24, chances are she is very connected with myspace, facebook, etc. Post a profile there with all of the information you can regarding her adoption. If she's looking, she WILL find you.
Make it possible, even remarkably easy for her to find you. Let her come to you. If she isn't looking, she isn't ready yet.
at 11:23 AM on Jul. 2, 2008