It seems like your girlfriend wants to marry. Probably her signs are mixed. And you have no idea how to decipher them. Let's see what signs point out she really wants to become your wife.
She jokes about your future talking about your children. She even knows their names and what they are going to do. And she says directly that you are the only one who could be a father of her children. She asks you whether you want children. But she says that she simply wants to know your opinion. Nothing else. She tells you that you are a perfect man. She admires you. All her previous relationships were mistakes. You are the only one she wants to spend time with. Talking about the future she wants to hear your opinion.
She says that almost all her friends got married. And she talks about it quite desperately. She is ready to spend hours watching wedding pictures of her friends. She admires them and really feels glad for them. Sometimes she even tells you how the wedding day would look like. She is dreaming about it. She even knows who she would like to invite. At the same time it seems like she is joking and not serious. Obviously she is waiting for your response and decision.
She wants to live together. Well, it depends on the situation. Sometimes it may mean that she is serious and your relationship means a lot for her. She asks you about your attitude to family and marriage. Well, she explains it by her curiosity. She wants to know what you think of it. She pretends as if she doesn't care much about it. And if you answer her that you would like to have children it makes her happy. For her it is a good sign.