Family Reunification Visa with mi soon-to-be Wife living with me in Germany.

My girlfriend and I live in Germany for 4 years and are getting married in Denmark, I am a peruvian with a Blue Card and a stable job and she is colombian with a Job Seeking Visa. Besides loving each other much, she is not finding any job and she has only 4 more months left of her Visa.

My questions are: once we get the Marriage Certificate does she automatically get a Visa or do we have to make a start a Visa Process? Are 4 months time enough to get the Marriage certificate from Denmark and get the Visa? Is there any other option we are not seeing that is faster and better than the marriage Visa? Please share opinions and stories.