Reducing family accommodation (FA) may be beneficial in cases of childhood anxiety disorders. Assessment of FA has so far relied on single-informant maternal report, which may be biased by factors including maternal anxiety. We compared child and mother reports of FA, and examined whether maternal anxiety moderates the association between mother and child report. Participants were fifty children with primary DSM-5 anxiety disorders, and their mothers. Mother–child agreement was good for overall FA and moderate for subdomains of FA. Mothers reported significantly more FA than children. Maternal anxiety moderated the association between mother and child report of FA, such that the correlation was stronger in more anxious mothers. Children agreed that FA helps them feel less anxious and did not agree that parents should accommodate less. FA is an important clinical characteristic of childhood anxiety disorders and assessment can be enhanced through child report and consideration of maternal anxiety.