Your post is way too general to give any fair comment, honestly. The only truthful answer is "who knows?"
How long have you been dating exclusively? How religious is her family? Have the two of you discussed important compatibility topics such as faith, kids, etc? If so, where do both of you stand on those topics, and how did each of you react to the other when confronted with opinions you didn't like?
you're really the only one who can decide that. Make the decision to research the organization from all angles and decide if it's something you could do. If you decide it's not for you, tell her early on and save yourself the trouble.
Some people can manage that type of relationship, but I'll be honest, it can really add a lot of stress.
Sure it can happen! It happened to me! I was LDS and met my "now-husband" who wasn't LDS and told me flat out that he would never convert and wasn't interested in my religion. I was as "Molly Mormon" as an LDS girl could be. We dated and are now married, he never converted, but I managed to "deconvert" myself!
Doesn't sound like it, but she's a new convert, and she maybe open to learning more about what she got herself into. Or she may have her sights set on some guy taking her to the temple to get married. She doesn't know anything about that, but she has probably been told that's a worthy goal.