This is beautiful, but the clouds seem a bit grainy. I do love the feel of it and the way it makes me feel like I'm lying in the grass. The blue sky looks pretty good also. As for the grainy cloud, I would suggest softening it (available on many programs) since the clouds generally don't need detail. Overall, a very bright and summery shot!
Lovely image, great colours and light looks surreal as if coming from under. It would work well as illustration for children's book - very charming, well done!