Please don't take this the wrong way but it almost sounds like you joined up because it meant you'd pretty much have someone making all your decisions for you, I've got a couple of friends who are officers in the army and to be honest they fully admit they spend more time basically baby sitting their men and sorting out their life problems than doing anything else and I mean if the lads could get them to wipe their backsides they would.
Please don't end up like one of these people who just follows what other people tell them or hope that someone else will make the decision.
Asking for advice is all well and good but your opening post almost sounds like a "Well I'll do whatever seems to be the popular opinion".
You're 22, you're in the Army and it's a dam good career if you make the most of it, don't go jumping to any decisions especially as it sounds like she's your first real relationship.
I'm 25 and I'd known my ex for over a decade since we were close friends at school, we started dating last year and it was great until she basically said I want marriage and kids before I'm 28, at that point I ended it because she was admiant that's how she wanted her life to turn out and I have zero interest in that I'm still young and living my life I'm in no position to be looking after a mini me and a wife!