This is the honeymoon phase. people daydream all the time about marriage and babies during this stage. They are not promises-just dreams "one day when I do get married, it could be with you which would be nice" etc Don't take it literally. You could break up in 6 months time. Nothing is set in stone in the first year so you should take your time.
She is moving too fast though. Tell her you have no intention of living together so soon. Plus you will need to be together at least a year or two and living together to get to know each other properly and suss out if you are compatible for marriage or not.
You just need to put your foot down and say no. Tell her you don't think its a good idea to live together in the first year and its not gonna happen.
"Don't ask a question if you can't handle the answer".