JQuery, retrieve children and grandchildren

Let's say I have a JQuery object which has (or points to) such a structure:

<div id="parent">
  <div id="child1">
    <div id="grandchild1">
      // ... grandchild can also have children
    </div>
    // ... and so on of grandchildren
  </div>
  <div id="child2">

  </div>
  // .... and so on
</div>

Is there possibility to get plain array of elements (JQuery object) from my object like this:

['parent', 'child1', 'child2', ..., 'grandchild1', ...]

Thanks

P.S. Please notice that it can't be selector something like this $('div > div'), because I already have JQuery object and only from this object I need take stuff.