Modify/add elements to element() variable

[Rob French]

Is there any way to add an element to a variable that contains an element()?

Example...

let $xml := <Parent><Child></Child><Parent>
let $snippet := <Grandchild/>

I want to insert $snippet into $xml/Parent/Child resulting in

<Parent><Child><Grandchild/></Child><Parent>

I know I can do this with XQuery Update but I would like to do it in
memory before actually saving the xml to the DB.

I know it is possible in a convoluted step where you create an
entirely new Child element with the Grandchild element added (along
with other Child children) and but then how do you add that resulting
xml structure to Parent? It seems like you would have to recursively
"add" new elements all the way up the tree.

Cheers