From a girl's perspective: don't propose until you're actually commissioned. Seriously. Think of it this way- If you can't make it 12 weeks long distance with a 1x/week phone call and an occasional email, then you certainly won't make it through 20 years of deployments, and PCS-ing every 3 years. Unfortunately, OCS will be the test you will need to see if you're both prepared to commit to each other for the long haul. She really needs to be ready to be your biggest supporter through this challenge and understand that you're no longer in charge of your schedule. At all. It takes a strong relationship.