She encouraged them to help Aang on his journey as the Avatar .
Kanna ( voiced by Melendy Britt ; portrayed by Katharine Houghton in the live - action film ) is Sokka and Katara 's paternal grandmother , informally referred to as Gran - Gran .
Sokka encouraged them to help Aang on his journey as the Avatar .
Kanna ( voiced by Melendy Britt ; portrayed by Katharine Houghton in the live - action film ) is Sokka and Katara 's paternal grandmother , informally referred to as Gran - Gran .