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.