Where can a 17-year-old girlfriend marry her 25-year-old boyfriend without parental consent?

You can't. In all states and provinces, as well as countries in North America, you must be 18 to get married without parental consent. If you really love each other then wait until you are 18. It's not that long away. You could get engaged and then look forward to marriage. The problem with this generation is they don't believe in the word "anticipation" and all the fun and excitement is gone out of it before they get there. Be smart, wait until you are 18.