Pastel Art by V.C. Andrews

I was wondering if this piece of art had any value. It is done by V.C. Andrews the famous author as a commission to a family that lived next to her years ago from what I was told. She didn't sign the art and I'm reluctant to open up the frame to look at the back of the canvas. I've researched the few other pieces she has done and you can tell by her style that she drew this. The back of the frame does have a sticker on the bottom with her name and address that she lived at in Portsmouth, VA. 
Would love your input on this, thank you.  R/Michael McFadden