Thank you for your question.
There are many ways to try and look for someone even when it has been such a long time.
If she is using a different name, I am sure she is still using her date of birth and she might also be using her middle name.
Some times people sue their middle names as their first, so you want to try that when you do a search and also the date f birthday.
What will happen is the middle name will match the date of birth.
Here are a list of nine to search engines that you can search.
She could be still in contact with old friends as well, so you might want to get in contact with them to see if they have talked or seen her. Often times people get in contact with old friends.
The very first thing you want to do is look up the person through an on-line search engine such as Yahoo! or Google. This will list information. You also want to type in last known address to see if there is a new address or if the person name has been changes. I want you if she has a middle name you want to type in her full name. If nothing comes up, I want you to put in her middle name and date of birth.
This site might be very helpful in seeking alternative to your search. http://www.futurescopes.com/advice/915/how-find-someone-your-past-locating-old-lover-or-friend-youve-lost-touch
If you need anymore assistance or anymore question I am here to answer. thank you.