 She played at SV Westfalia Weitmar 09, SV Waldesrand Linden, TuS Harpen and SG Wattenscheid 09 at youth level, before joining FCR 2001 Duisburg in 2004.Krahn was runner-up in the Bundesliga five times with Duisburg, including four seasons in a row from 2005 to 2008.She won the German Cup twice with the club and claimed the UEFA Women's Cup with Duisburg in the 2008–09 season.