Diane's mother is Meg Stuart. Diane was married and had one daughter, when shortly before her shift at the ED they separated. This threw Diane into a confused state and also left her fearing for her and her daughter's safety.
She began her shift in the ED and was immediately seen to be useless to the other members of staff, mainly due to her incompetence and vulnerability to make mistakes. She accidentally almost administered a patient with the wrong fluid which could have been fatal had Dylan not stopped her in time. Lofty later spoke to her about it and she begged him not to tell her agency as she was tired from little sleep the night before, but he told her he had no choice as a patient's life was put at risk.
Later in her shift, Diane attempted to prove herself to Lofty that she could be more competent. When the patient from earlier was re-admitted, Diane assisted Lofty and Dylan in the lift whilst escorting the patient upstairs to the heart specialists. When the woman went into cardiac arrest, Lofty decided to use the defibrillator to shock her. When the first shock didn't work, he administered a second. However, Diane had lost concentration on Lofty's instructions and didn't get her hand off in time, and received a shock and fell to the ground. She was quickly rushed into resus but with efforts from both Zoe and Lofty, she was unable to be saved.
Behind the scenes
Catherine Skinner portrayed Diane for two episodes in 2016. In her second appearance, she appeared with no lines as a corpse but was heard via a voice message she had previously left over the phone. In "High Tide", her voice was heard again but this appearance was uncredited as she did not appear on screen and it's possibly archive audio was used.