--- a/accessible/generic/DocAccessible.cpp
+++ b/accessible/generic/DocAccessible.cpp
@@ -1879,20 +1879,23 @@ DocAccessible::ProcessContentInserted(Ac
       child = GetAccService()->CreateAccessible(aNode, aContainer);
     }
 
     if (child) {
       TreeMutation mt(aContainer);
       if (!aContainer->InsertAfter(child, walker.Prev())) {
         return;
       }
+      // Create subtree, including moving grandchildren and adding those
+      // grandchildren's hide and show events, before adding the new child's
+      // show event.
+      CreateSubtree(child);
       mt.AfterInsertion(child);
       mt.Done();
 
-      CreateSubtree(child);
       FireEventsOnInsertion(aContainer);
     }
   }
 
 #ifdef A11Y_LOG
   logging::TreeInfo("children after insertion", logging::eVerbose, aContainer);
 #endif
 }