My girlfriend and I have been going out for a long time , things have gotten more serious we are talking about getting married soon, she is basically telling me I will be the provider of anything that involves money , e.g.. Buying a house, paying the bills. She has a some debt and spends every penny she gets , which in my eyes makes it hard for me . What should I do to make her understand that her spending habits need to stop and to start thinking of our future?

My putting off the next step in our lives has upset her to the point that she wants some time to think about us and our future.

That is an excellent idea as all finances should be discussed and resolved before the I do's. I'd say wait until everyone is on the same page and in accord. No one can tell the other what to do so, start the negotiations.

It is called a budget, and you and her need to sit down now and discuss it.

It does not have to be a tight budget, but she also has to understand that part of her money will be going into savings and paying part of the bills,
Each of you can have some funds for "spending" but it is going to be a partnership.

** Unless you have a job paying in the 100's of thousands and can just pay the bills, In which case I have a great grand daughter for you to meet.

Sorry, I may have this wrong but she seems a bit selfish!

She does not seem to have her priorities in check, proven by her continuous spending habits which you clearly point out.

Before marriage, she needs to learn financial responsibility..

This is important and one person cannot be expected to take on this responsibility. You really need to discuss this with her. I have this feeling though that she won't want to do that. One you mention this concern to her, she may walk because she knows you will not support her while she continues to be irresponsible with money.

I am sorry if it sounds like I am slating her (do not mean to), I know you must love her.. All I am saying is that with a commitment like marriage comes a commitment to joint responsibilities, including financial ones.

O.K if you earn more than her, or she has huge debts, then it needs to be budgeted in such a way that you pay a higher fraction than she does.

I bet she uses her disposable income to engage in retail therapy which ultimately is probably the vicious circle she is now captured in - - Namely Debt.

Well, she certainly needs to do a lot of thinking about her future and how her lack of money management skills are going to impact it. You should flat-out explain to her that, as you said, her spending habits need to stop. Inform her that she cannot just spend every penny she earns. She'll need to contribute to the household costs as well. If she is unable or unwilling to do so, then I believe you're quite wise to rethink the whole thing.