Wow! Daughter looks a lot like mom! I would bring the mom in a lot closer... with her standing so tall it looks like she's separate & distant from the dad & daughter. Also, zoom in. For family shots, the closer your subjects are to one another the better. It's all about touch, closeness, & faces. Hope that helps a little!
A tad dark for my taste but nice composition. Lady is too much in the shadows and front edge of chair and second button on man is a little jarring. Girl seems too burnt compared to the rest of it - 6
The lighting in this "portrait" doesn't work if it is to be a "family" portrait. The way it is lit, all the attention goes on the girl in front, with some attention on the dad, and the mom being an after thought.