Involving children in a participatory research design entails certain ethical challenges that require the researcher to consider how to respond and act ‘right here and right now’. All child and childhood researchers are familiar with their obligation to inform and obtain consent from parents and teachers, before involving children in research. However, even with the signed consent, the research can easily take another direction than first planned. This study explored how involving children in research forces ethical dilemmas in-situ which require a ‘right here and right now’ response from the researcher. Data from this study were gathered through the multi-method mosaic approach. Originally, this study focused on children’s learning paths as they transition from pre-school to primary school, however, when analysing the transcribed and coded data through a constructivist grounded theory, we revealed micro-ethical moments where the research repeatedly took another direction than first planned. Thus, the research topic changed focus. Based on the analysis of interview transcripts, two types of ethical considerations emerged as important when involving children in research: (1) researchers’ response in-situ when micro-ethical moments occur (2) continuing the data collection when the research topic is changing. Considering this, the results point to a need for reframing the research design which includes what we have termed ‘ethical sensitivity’ when it comes to processual aspects of data generation. The process may entail arising ethical dilemmas, which in turn may influence how the children participate in the research and the generated data.