Very little is known about Coello-Bannon's background, including why she chose to pursue a career in producing. She first got work as an editor on the 1986 film Scorpion. Then, she became an associate producer for Cop Rock. After co-producing a number of TV shows, Coello-Bannon became a co-producer/associate producer for the police-procedural drama series Criminal Minds. In Season Three, she was promoted to a full-fledged producer. In Season Eight, she was promoted to supervising producer. Starting in Season Twelve, Coello-Bannon is a co-executive producer.
Coello-Bannon served as a consulting producer for the series.