We have been together since sophomore year of HS and now we're seniors in uni. So we're going on 6 years. We had a group of friends go out after class tonight for dinner at the campus bar. Long story short my girlfriend and her friend jokes about who's going to have kids first and her friend commented" well you to are practically married already so you got a head start." My girlfriend responded by jokingly punching my arm and saying " someone has to propose to me first then it's an option." Marriage doesn't sound bad but I'm in my early 20s and it's sounds weird to be engaged so young.
Its not weird at all, its the best time for marriage because your young and you get to experience the joys of marriage life as a young couple. Most people can't experience marriage the way they wanted to in their 30's or 40's. But she did hinted that she does. If not her, its definitely her body signaling that to you through body language. 6 years is more than enough time since you've been a high school couple to figure out if you want to marry her or not. Do you not see yourself as her husband? I say you two need to speak on this now. Don't wait, speak up.
Don't let the lives of people around you affect yours.
Marriage comes with a lot of responsibilities and, unless you're confident and sure that you have reached a stable point in life then don't even think about marriage. If she loves you then she should respect your feelings and decisions towards it too.
6 years is quite a long time. Perhaps the lovey dovey activities you did when you first started dating haven't been happening as often as they used to so she's starting to feel insecure. Assure her that the love you have for her remains, if not, growing even larger and if she really wants physical evidence then engaging in your early 20's isn't weird at all if marriage doesn't sound weird to you then. A greater emotional toll is created with a divorce than breaking off an engagement.