Families waiting for an Autism Spectrum Condition assessment often experience difficulties explaining, or making sense of, the referred young person's behaviour. Little is known about this sense making, or how clinicians might support this ambiguity. This paper explored finite details of how five families do "sense-making" in conversations with each other, while on the waiting list for an ASC assessment. A Discursive Psychology analysis of these conversations found that sense making was affected by (1) an interactional pattern of interruptions impeding the progress of sense making narratives; (2) face saving to maintain positive identities and shared understanding; and (3) difficulties in word finding within sense making narratives. These practices challenged the production of a coherent family sense making narrative.