This study seeks to build an explanation of the sociological, psychological and political processes and practices involved in relationships between mothers and practitioners, as generative and causal powers that underlie and shape this. Critical realist’s primacy of ontology forms the starting point, with grounded theory as the epistemological force providing critical realism's method, contextualising research and embedding this more firmly into practice. As such, this article offers critical realist grounded theory (CRGT) as a tool for contextualising parent-practitioner relationships, drawing on retroductive argumentation, which involves moving from the level of observation and lived experiences to making (non-linear) inferences about underlying structures/mechanisms that may account for the phenomena. Thirty-four participants participated in six in-depth focus group discussions; three were with early years practitioners and three with mothers of children aged between 2-4 years old. Focused coding led to themes reflecting the lived experiences of mothers and practitioners, namely being valued, relationships, what happens at home, child at the centre and when I am not there. In line with CRGT, multiple causal mechanisms (including the interpretations of each situation made by individuals) were identified that were active in the situated contexts. In order to improve relationships between mothers and practitioners, attention needs to be paid to the psychological, social and political forces at play, as generative, causal and contextual powers, that have an impact on the status and relationships of the players within this triad (mothers, practitioners and child).