If my fiancé has DACA right now we are getting married in October, can she get green card without living the country?

More information is needed in order to provide a legal analysis of eligibility for adjustment of status in the U.S., including information about your fiance's immigration-related history. If you are a U.S. citizen and your fiance entered the U.S. lawfully and with inspection, but then overstayed her visa, you indeed may be able to sponsor her for adjustment of status - a process that would not require her to leave the U.S. and pursue consular processing. Of course, there are many other details that determine eligibility. It would be wise for you and your fiance to consult with an immigration attorney who, after learning all of the relevant information, could advise about eligibilities, options and strategies to attain your goals, and who then could offer legal representation in the often complex application process.