A Decision which Could Affect the Rest of My Life...

You can't go into a relationship saying to yourself "Yes, I must definitely marry this girl" just because she says that that is what she is after. It's far too naive to assume you will both fall in love and stay in love and weather the storm of future and unpredictable conflicts long enough to want to get married.

I don't think you should put yourself under so much pressure before you're even dating this woman. If this is a concrete demand of hers before you can get together, then she's being unreasonable and you should look elsewhere. If it's just something she hopes will happen, understanding that there are plenty of Ifs and Buts along the road, then go ahead and date her and have fun.

I don't think you can honestly say for certain any more than she can that you want to get married to someone you haven't even dated yet. Friends for years is one thing, dating is another. There's no rush; keep your options open.

Jam it back in, in the dark.