I'd wait on the whole marriage thing and see how she acts when you don't see each other for a week (or multiple weeks) at a time. That sort of separation can be deadly. Sure it's all fun and games now while you guys are at the same college doing the same thing in the same classes...what's going to happen if you're working for different companies with different schedules and different bases? I consider myself very lucky to have found the person I did who can handle only seeing me 1-2 nights a week and knows I'm not out there screwing the help.

This girl may be "the one" but you won't know that until you go through a variety of situations with her...not just the college stage. Get out in the real world and see if you still feel the same way, THEN decide if you want to marry her.