That's not your job yet. That's what her dad is for.
Shackin' up and playing house is not a good option either. If the relationship goes south, now you're both in a bad way. Support her emotionally and be there for her and that's it.
Be a sounding board for her ideas and know that some of her ideas are just her thinking out loud and don't require your input.
If something seems like a sketchy idea or not well thought out, ask questions that help her lead herself to a logical conclusion.
If she is the type of woman who needs to be told what to do and require constant handholding, she may need to spend more time at home with mom and dad anyway.
Do not get into any financial arrangements jointly. Should the relationship fail or falter, it could screw up both yours and her credit. Should you ever get married, it would be nice for at least one of you to be able to get financing for a car or home-traditional style mortgage or loan.
Keep in mind that the economy sucks right now and good paying jobs may be few and far between depending on what her education and work experience is. Trying to play daddy warbucks can break you-especially in the early years. These are the years to be building your financial foundation.
It's never too early to start saving for your retirement and it always works well as an excuse for not having extra money around for discretionary lending.
If you do this, you will not only win the respect of her, you will also win the respect of her parents. If this were her asking the question instead of you, I would be saying the same to her.
Been happily married for 14 short years and it works.