A great work! It kinda tells a story doesn't it?
I'm not exactly an expert on photo manipulation but here are some helpful advice. Make the ripples start from the base of the girl so the blending of water and she will be more seamless. Also add a little bit of blur. It would be great to add some grass over the horse layer as well as a shadow under it. Also consider the lighting. It would add more emotion if you showed more light rays above some layers.
I love how the girl's face is hidden and the play with contrast and saturation. I also quite like the look of the horse. He looks pretty curious and concerned to me. Which adds emotion.
Overall a great great piece! I hope to see more of this in the future. You have just been added to the watchlist.