This systematic review aims to identify and describe how children of parents with mental illness, substance dependence, or severe physical illness/injury, experience and practise their everyday life. The review followed the four stepwise recommendations of Harden and colleagues when including quantitative and qualitative studies on peoples' experiences and views. In all, 23 studies with data from Norway (2010-2022) have been included. Brown and Clark's thematic analysis was applied. Three themes were constructed from the reviewed articles: (a) Children practice their relational agency by actively doing practical tasks, occasionally jobs to maintain family economy, and organising fun activities with the ill parent. (b) Emotional ambivalence when their own needs were set aside in favour of the parents. They loved their parents but also felt guilt, anger, disappointment, shame, fear of inheriting the illness and longed for a 'normal' everyday life. (c) Supportive contextual factors were, for example, at least one significant adult recognising them, participating in leisure activities, socialising with friends, and talking with other peers who shared similar experiences as next of kin. Obstructive factors were lack of information and recognition as well as silence and lack of dialogue within the family and/or health professional.