This paper discusses the role of mediation as it arose in developing and teaching two online American Sign Language (ASL) courses for parents of deaf children during the COVID-19 pandemic. Deaf children and their families who are still acquiring ASL have ongoing learning needs that are most often not met in mainstream educational systems, and these inequities have deepened during the pandemic. Combining reception, production, and interaction, mediation is a mode of language activity in the "Common European Framework of Reference for Languages" (CEFR) that involves "languaging" to develop ideas and facilitate understanding and communication. In this nine-month study, intensive parent ASL courses were adapted and developed for rapid implementation of online instruction in order to meet the second or additional language ASL learning needs of parents of deaf children. Online questionnaire, interview, observational, and assessment data were gathered regarding participating parents' learning processes and experiences. As study findings reveal, a main theme that arose was the role of mediation in terms of alleviating various barriers for participants and facilitating the linguistic and cultural dimensions of parents' online ASL learning and understanding through cognitive and relational means.