title: Can I listen to the children property in $ref
body: <p>if an element renders its children later and I have a ref to the element, can I listen to changes to the children property?</p>
  <pre><code> &lt;element ref=&quot;parent&quot;&gt;
      &lt;child-to-be-loaded-later /&gt;
   &lt;/element&gt;
  
   watchers: {
      '$refs.parent.children'() {
         // do stuff here 
      }
   }
  </code></pre>