Fetch the children as count and then do an section show on the number of children... Pseudo code:
{let number_children=fetch(content,count,hash(parent_node_id,$node_id))}
{section show $number_children.nq(0)}
do your work on the children
{/section} {/let}
My syntax is probably wrong, do some search on EZ to find the correct one.
{let children=fetch(content,list,hash(parent_node_id,$node.node_id))}
{section show=$children loop=$children}
{$:item.name}
{section-else}
You don`t have any children
{/section}
{/let}