Hi I want to find a girl I used to be (very good) friend with (we were 8 years old)
I have her full name but nothing on google / facebook, have you got any way to find her using the Internet?
Have you tried looking up her immediate family? I don't know how old you are, but if she's never owned a residence you're more likely to find her parents/guardians under whitepages, especially if you have an idea of what state/region she might be in. Slblings could show up for something to do with school.
Even if you don't know her parents' full names, something like last name + occupation (if you know what they did) could turn up a professional page.
Try other search engines to see what you get. Since you know her approximate age, add that, her birth date, the state/region you knew her in, anything else you can guess in various combos -- even age + first name + state might end up finding her in some newspaper. If her name has any sort of common shortening or nickname, look for her under that also.