Early in her career, she worked with the Univision network in Miami, Florida. She moved to Telemundo-owned station KTMD in Houston, Texas, from 2004 until she joined NBC-affiliated station KPRC-TV as a general assignment reporter and weekend anchor in 2006. Known for her dynamic reporting, she has covered many prominent news stories, including Hurricanes Ike, Dolly and Gustav. She was one of the first reporters on the scene to cover the 2009 Fort Hood shooting. In 2012, she was named co-anchor of WMAQ-TV's weekday morning newscasts along with Stefan Holt, replacing Rob Elgas and Zoraida Sambolin, who returned to the station in 2014. In June 2014, Guzman joined KNBC in Los Angeles as a co-anchor of Today in L.A. alongside Whit Johnson after Alycia Lane left the station in 2013. In May 2016, L.A. Parent Magazine hired Daniella as a contributor to the magazine, the magazine debuts its column "On The Record: Straight Talk For Moms" in which, she is now also a magazine contributor in addition to its anchor duties at KNBC.