Military Decision...?

I have, after thought and talking with a Army recruiter, decided I want to join the military. I need some advice on another topic though- my fiance. My fiance supports me in my efforts, and has said she would like to come with me and bring our two children. Now she is having second thoughts about how to transition and how she feels about being committed to a new lifestlye and especially being married. SHe seems to think that she will be all alone and if we fight or she gets upset she has no where to retreat to. My problem is how to not just convince her but win her whole hearted support for this endeavor. Joining without my kids and fiance (our biological children together) woud really hamper my efforts. I think she ought to suk it up and be strong and support me and see it is some pain now for a better future. But, that sentiment isnt hers lol! Before you retort, allow me to explain, she comes from a very turbulent family. Her mom has moved all over creation and is not what you would call a model citizen. SHe has a few family that she is close to- siblings-. They seem to be very important to her, thus her families opinion has significance to her. She has not had a very grounded, structured and stable lifestyle. She says she wants a stable and structured life, but it seems to have her headed for the hills I guess, hell, I dont know, she seems flighty and was once a supporter, now has become a stick in the mud. I need help and quick!