As linked above, Fortuna knows where the lab entrance is. She will tell Ramza and Yu, and may tell others but is not likely to unless she trusts them.

She will tell anyone who wants to know about the Rangar (details pending completion of a certain log), however, provided they don't seem like they'll rat them - or her - out.

If there's anything you want to know in particular, tag me and we can see if something can be worked out!