A religion is a story, a narrative, a collection of beliefs, rules, written many years ago with symbols etc. But Christianity is more than that, Christianity is about the current relationship with God. It isnt just about stories that occured in the past a thousand years ago, it is about the stories and experiences we undergo now. You may not listen/agree to that, but that was the point he was making, so accept it or move on.
OP if all she talks about is God God God then she seems to be pretty serious about her faith. Try to talk about other things that may relate to that e.g Christian societys, or praying for countries around the world. Then develop it into a deep conversation about other things. You said you wanna know about her, well appreciate that atm God is clearly important to her. Maybe you could also ask how she became christian, if her family are also christian, then move the conversation away from that and unto you guys' uni life etc like how she is finding uni and so on.
A conversation is meant to be between two people, if she has control of it then she isnt really letting you have your say which isnt fair. You should be able to have some sort of input that can sway the direction of the conversation.
Feel free to ask more questions, it would be my pleasure to help