When a girl calls you by your full name?

So I met this girl at a summer program a couple months back. Been in and out of contact ever since. Recently she started contacting me again and being the nice guy I always am I replied back.

Funny thing is, she ALWAYS addresses me by my full name, ie If my full name is Benjamin Brown, She would call be Benjamin Brown, not benny not ben not even benjamin. My first name AND my last name.

Now I actually sorta had a crush on her but guess I gave up on that because she either wasn't interested or didn't get my hints.

Errmm so yeah if someone could tell me what's up with that would be greatly appreciated... I know this question sounds super lame but yeah just wanted to know.