I agree with all those who said her approach to money and saving is more alarming than the debt itself.
You need to be somewhat financially compatible. I'd have her read Mr. Money Mustache and see what she thinks. People can change. It may open her eyes.
Since you've only been serious since the summer, I'd give it some time, but also have her know that living a frugal lifestyle is very important to you.
Ultimately if you can't get on the same page, I'd be very, very careful about getting hitched.