Well, if she [i]loves[/i] Destiny as much as you say, and she instantly recognises the Destiny app from a glance at your phone, then it's pretty clear she comes here.
Even if she hasn't got the app, she probably accesses it through the website. Game news and updates, finding herself a Fireteam, lurking on #Destiny and #Offtopic - Why wouldn't she?
She definitely knows. You've just proven your a weirdo, now she wants nothing to do with you.
[spoiler]Lol just playing but srs m8[/spoiler]