OKAY MY FRIEND! Remember when i said older women can be manipulating and controlling? Well this is it. Before anything i'd like you to ask yourself and be honest with yourself. Don't worry about an internet stranger trying to give you advise on something that will either make your life happy or make it the worst. DO YOU truly love this woman? Does she make you happy? Do you want to be with her? Are you ready for it? Be honest with yourself about the answers. If most of them are "NO" then my friend DON'T MARRY THAT WOMAN!
On the other hand, just because she's pressuring you to marry her doesn't make it wrong. Kumbuka there's shame to bear especially in our cultures with women who have kids out of wedlock. I know Tanzania is evolving and things are changing, but if she's older than means her thinking is also stagnant to the ideas and influences of older generations. You can't fault her for that. But what you can do is COMMUNICATE with her. Ask her why marriage, what's the rush? And if you plan on marrying her some day, be honest with her. Tell her that you will marry her but your not ready. And why aren't you ready if your not? She'll demand an explanation and rightfully so, give it to her.