Maggie McKiernan is a female resident of Holby.
At some point, Maggie's husband James fell off a ladder and broke his neck whilst building a music studio for him and his son Aaron. This left him tetraplegic, and Maggie was left as his primary carer.
On 11 May 2019, on James' 40th birthday, he began to seize, and Aaron unsuccessfully tried to stop him from rolling off his bed. Maggie heard the commotion, and, horrified, she blamed Aaron for what had happened. Once the paramedics arrived, she berated Aaron for refusing to accept treatment, but paramedic Iain Dean promised him that he would have him seen to as quickly as possible.
At the ED, Iain told Maggie that Aaron would only be treated if she was there with him, but she insisted that he was just being difficult and opted to stay with James. Later, registrar Archie Hudson informed her that James' chest infection had rendered him inoperable. Devastated, she lashed out at Aaron. Iain tried to tell her that he was scared for James' health too and claimed that he was not to blame, but she begged to differ. Aaron pressed her to admit that she blamed him for his father's accident, and she scolded him for taking his foot off the ladder.
Outside the ED, Maggie started to panic when she received a phone call from Aaron, and Iain accompanied her back to the house. There, they found him with a dislocated open fracture after he had caused the incomplete studio to collapse on top of him. With Maggie's help, Iain managed to relocate the fracture, and she apologised to her son for her treatment of him. At the ED, she thanked Iain for his help. (CAS: Series 33, Episode 34)