Aunty Kath is Fin's mother and Mum and Brendan's sister. Because her husband died about fifteen years ago, she's mostly on her own in taking care of Fin in the aftermath of the accident. Tom describes her as an exceptional cook, especially when it comes to birthday cakes: she always made Fin amazing cakes, which he believes she did because Fin's birthday was always overshadowed by Daniel’s. This implies that Kath was aware of the dynamic between Fin and Daniel and attempted in small ways to fix it. In the present, Kath has become extremely strong and muscular from needing to lift and turn Fin. She spends most of her time with him at the hospital, caring for his every need. During a brief visit to Gran's house, she loses her composure when she discovers that Mum is spending all her time in bed and is neglecting Tom and Kylie, to whom Kath is especially close. Her explosive anger is enough to encourage Mum to get out of bed more often and begin to recover. Kath does what she can to make things as normal as possible for Fin. She arranges a birthday party for him in his rehab facility and purchases a flat near the hospital and rehab center so that Fin will be able to move home. Despite everyone's relief that Fin will be able to do so, Kath is vocal about the fact that Fin is afraid. Dad implies that Kath is also afraid and overwhelmed by the task of needing to care for her adult son. She never sees Daniel in jail for the duration of the novel, but she and Fin do express interest in doing that at some point.