Her facial details are very well done. Youve captured a moment in time of a child asking or saying something to the viewer, making this a personal moment for him or her. Her look of innocence mixed with curiosity and expectation draws you right in to the wonders of her facial expression. Her presence is very compelling, pulling your attention fully on her.
You caught the details of her nose, mouth, eyes and eyebrows beautifully and her fine hair with its highlights reflecting the light source like silky strands.
The way you highlighted her face makes it glow with the light source from the left but you also included a reflection of the light bathing her entire face seemingly coming from everywhere. It bounces off her face in a diffused manner, highlighting the outer edges of her face, her chin and jawline and really highlights her sparkling eyes. This gives her face luminosity and it looks like an inner radiance is coming out. This is perfect!
I do think the background should be much more vague than youve rendered it. I would like to see it all one soft blue color like youve used on the top half, with just small variations so it doesnt look flat. This would add to the luminosity of the lighting seeming to be coming from all directions.
Everyone who sees this painting will love it. There is no other reaction possible! And as she grows this painting will gain in value.