Kristen graduated from Marathon High School in 1983 and then got her BA degree at Washington State University for Interior Design in 1987. During that time her mother and father Wayne and Elaine Brenner both well known Realtors of Duck Key who established Brenner Realty in 1977, insisted that she study for her Real Estate License on Spring break in 1984 and that summer she got her Real Estate license.  Upon graduation Kristen came back to Marathon with her BA in hand to work for Richard Renard, Architects with dreams of going to the big city of Miami to a larger architecture firm. Two years later she took over the Brenner Real Estate Company and her parents were retired.  Kristen changed the name to Duck Key Realty in 1999.  Kristen was married in 1998 to Eric Kreizman and they have a son Elliott who was born in 2000.

Kristen has been top producing agent in the Middle Keys ranking as one of the top 5 agents in the Marathon area for the last 10 years. No single agent has sold more real estate on Duck Key than Kristen.

After the financial melt down of 2008, Kristen has been a part of the American Home Mortgage Servicing team of Monroe County handling bank REO's from Key Largo to Key West as well as the sales of properties in Duck Key.

In October of 2009 Duck Key Realty merged with American Caribbean to be their Duck Key Division.  Currently Kristen is the Number One agent in the Middle Keys market (7 Mile Bridge to Long Key) for the year 2009 and the Number 2 agent Keys wide.