Metaphoric Poem by Mark

This is poem my son Mark wrote for an English assignment.  
Warning: Get your tissues out, it is pretty darn sweet.
My Family Tree
By:Mark Hoog
My Family is like a tree.
My mom keeps us upright and healthy.
Like the roots of the tree she provides us with food and the necessary resources we need to grow.
My dad is the crisp brown bark of the tree.
Like a shield he protects us from harm and takes the brunt of the storm.
My brother is the deep dark gnarled hole in the tree.
The one that holds many secrets and treasures but no one is sure how it came to be or how to access it.
My sister is the leaf that dances, swirls and sways in the swish of the breeze.
The leaf that exhibits the full beauty of the tree yet, easily is damaged when the storm gets to strong.
I am the trunk under the bark that holds the tree up right and helps support the tree when the bark is missing. I am there, always there, to help the tree.