Overall I adore this picture, it looks like something I'd love to see in children's illustrated book. You've created this fun, bright, sunny mood and it's wonderful.
It's amazing what you can do with simple color pencils! The colors are great, they blend flawlessly, and I love how you've shown the textures with colors. The only thing - the picture looks a little flat to me, because the background is as bright as foreground. You could bring the girl and dogs a little forward by making the ouline thicker or the background dimmer. Also, the background is not quite as well color-balanced as the foreground, but maybe it's only the matter of taste.
But your shadowing is perfect - characters really have volume to them.
Also, you clearly have your own style and I relly admire your it. It draws the viewer closer to the picture, it's adorable and original. Great work!
Just want to wish you luck and improvement and hope my cririque was useful.