Perspective/Camera Angle question

[demotlj]

I'm struggling with trying to figure out the proper placement of the horizon line in a picture I am doing for a story. In the previous scene, a donkey carried her rider through a break in a stone wall into a vineyard. Now the donkey is climbing a rocky slope and as she crests the rocks, a flock of partridges flies in her rider's face. I want the camera angle low so that the partridges and rider have the sky behind them but, for the flow of the story, I would also like to be able to see the stone wall and vineyard in the background. They don't have to be super visible, but at least there somewhere to help the transition. Short of building this whole scene out of blocks, is there a way to figure out how much field of view a camera would include and where to place the horizon line? Here is a very simple sketch from the side of what I am trying to do (leaving out the partridges).

And here is what I have come up with so far for a rough sketch.

I also realize that the rider should be sitting farther back on the donkey but then you can't see him very well so I decided for the purpose of the story, I'd ignore proper riding stance.

Any help would be appreciated. Just doing this all for fun but I'd still like to do it right
Thanks.

[Lawnz]

@demotlj All you might have to do is raise the horizon and relocate a bird or two to get the desired effect.
And as long as you keep your foreground darker than your background, you should get a real sense of distance and height.

[demotlj]

So, for what it's worth, here is the final painting.