You’re rushing. Chances are high that you’re going to be ignoring things you shouldn’t in an effort to rush to meet the image of a stereotypical nice life.
Most people who do that think that, as long as they meet these arbitrary goalposts, they’ll have life figured out. It’s usually a way to mask insecurity.
You seem dead set on rushing into this marriage based on your comments so far and it’s sad because who your girlfriend was at 14 and is now will be different from who she is at 21 and she should have the chance to grow without already being locked into a marriage (which might seem fun to her now) and especially without being locked into an eternal commitment like having kids.
I know us telling you that it’s better for her to develop into an adult before she chooses to marry will probably make you want to double down, because the possibility that she might not want you as a husband anymore if she grows up a bit more is superscary and you think that if you just rush into marriage now you can avoid that possibility. But deep down I think you know that putting your own needs over that of your partner is selfish. If you love her, you should protect her and support her and in this case that also means protecting her from herself because she is still so young.
I know this will probably all fall on deaf ears and you were looking for reassurance that it’s fine, but if you take one thing away from this please, for the love of God, don’t have kids until you are 25. If you have kids now, they will be a massive strain on you both and your relationship and your relative immaturity will mean that you can’t even provide for your kids in emotional security properly. Don’t create two broken lives just because you’re trying to fix yours.
No, that’s precisely my point. I don’t think you are decades older and extremely experienced. I think you’re both still very young. I’m not ascribing nefarious motives to you, I’m trying to let you know that rushing towards this dream without the proper base of maturity will not bring you what you dream of. You’ll just be sabotaging yourself by not allowing the both of you time to grow (and discover that your dreams might shift). There is no need to rush.
And yes, in my message there’s more concern for her than for you. For one, she is even younger than you and hasn’t known anyone else romantically since she was a child. You’ve mostly talked about really wanting to live up to your dream and only now say it’s a dream you share. There are many dreams teens (or even adults) share out of enmeshment and going along with someone because you’re not quite sure what you want yourself.
If you didn’t come here for the actual opinion of people who might actually have more experience than you and if you can’t handle the perspective of people telling you it’s a bad idea, why did you come here? For validation? You’re feeling misunderstood by me and others but that’s because you don’t want to hear the core of what many older people are trying to tell you. Regardless of love, of perfect fit together, of intentions, it is a bad idea to get married this early. That’s the answer to your question. Are there exceptions? Yes. Do I think you are one of those exceptions? Odds say, no.