When I was about 27, I had been a Christian for two years. Two Morman missionaries ended up on my doorstep, and they gave me a copy of the Book if Mormon to read. They told me to watch for a "burning in my chest" when I read it.
So within the first couple of pages, I found three direct contradictions with the Bible. There was no burning, and it was apparent that the Book of Mormon was neither holy nor true. I gave it back to the two missionaries, and pleaded with them to leave the cult, after showing them the contradictions with the Bible. They were kind of stunned and left.
So so my questions to you are:
Do you know Jesus Christ as your Saviour and Lord? If not pm me and we can talk about it.
Do you read the Bible consistently every day? I had already read the Bible through completely two times after being saved for two years. I had a lot to learn, but I knew enough to recognize the counterfeit when I saw it.
Never let your passion for a girl convince you that Morminism, or any other cult is right. Mormons are all trained as missionaries. She may be just trying to pull you into Morminism, rather than caring about you. And she is setting the agenda, if she is trying to get you to read the Book of Mormon. Instead, you set the agenda, by using the Bible as your guide, not an extra biblical book, claiming the list 10 tribes of Israel were in America, and there is lots of archeology to back it up, when there is in fact not one single site of Jews in America after the 722 BC dispersal by Assyria of Israel.