Is Everyone On Facebook Searchable Now?

[Unique]

Yes.,
There are many Questons like .The Name you know may not be her Username on Facebook etc.,
Here is the solution for it.,
Facebook has extended the features.,
DATABASE has been extended a lot.,& every person can be traced(securing the profile viewing from strangers has been recently removed by Facebook)

SOLUTION FOR YOUR QUESTION:
CASE 1.These days every body creates a event/page on Facebook for parties.,If you remember the name of party open it & start Tracing her with details what you know About her.,
CASE 2.: If any event/page is not created.,
Type this in search bar
1."people who study at (college name)" & then start filtering.,
2."people who like(what you have observed from her) " & then start filtering
The common profile which you observe is her profile.,