WhiteWolf1inVA. I am going to put myself in her shoes for a minute. One of my best (female)friends is in this exact situation right now. The reality is, a once-scalded dog thinks twice, and that's just the way it is. She got really burned by a guy who made all these promises and ran out on her.
On the other hand, I think you have very valid points. I think six months is a fairly short time to find out if you are ready to spend the rest of your life with her. I was totally in love with a woman, whom I had been dating for about a year. It was early Winter and I was planning on asking her to marry me the next summer. She was pressuring me to get married, but like you, I wasn't going to do it because I was being pressured. Then I saw her temper. After seeing her fly into an absolute rage at a coworker, who really hadn't done anything wrong, I've worked in two psychiatric hospitals, and she shocked me she was so out of control. We're not talking your average "pissed off" here. I found out I wasn't the only one. I learned she had been arrested, literally, for domestic violence in her previous marriage. She definitely had a problem with anger. I realized real quick I didn't want to spend the rest of my life with her. She had been able to keep this hidden for a time, but over time someone's true colors come out. If we had gotten married at the six month mark, then I would right now be in an absolutely horrible situation, probably sleeping with one eye open.
I think your statements that you're definitely going to marry her come off as a little bogus because, if that were really the case, you already would have. I think the way you put it is very accurate. You like the way the relationship is going, but you want to be sure, because you want it to last forever.
You also need to be sensitive to the fact that she's feeling extremely insecure. She probably hears her clock ticking and is wondering if she'll ever be a wife. I think you have to be sensitive to that. I also think six months is too darn short. I know there are a lot of short-courtship marriages that work, but you run the risk of missing something major.
Ultimately, this is a conversation that you and she have to have. If you are totally honest with her that you think six months is too short, she'll see that you're being sincere and that will help her trust you.