Maggie Coldwell was tough, fair and professional. However she was always prepared to be a maverick and go against management if it meant doing the best for a patient. This outspoken streak held her back from progressing up the career ladder, despite her great competence as a doctor. She was a good listener, and gave non-judgmental advice. Maggie started off her career in medicine as a nurse, before retraining to become a doctor.
When her husband Steve was sent to jail, Maggie lied to her two children, telling them he had died. When they discovered the truth and he was subsequently released, she allowed them to travel abroad with him to Malaysia. Maggie's daughter Joanne returned to Holby and Maggie was shocked to see that she was heavily pregnant. Joanne gave birth to a baby girl called Lana and Maggie ended up sharing her house with Joanne, Lana, Toby de Silva and Ruth Winters.
Maggie finally decided to leave the ED after she was wrongfully accused of causing a patient's death. Although she was cleared by a coroner's court, she decided it was time to put Holby behind her.