What kind of animals are you imagining being in that area? Generally, a pen/pasture would be much larger than that. Then again, if this is a kind of house that will be repeated many times in a single village or city, then I think you've got a good one right there. All I would change is the shed in back ought to have a slant-roof to keep rain off, and the shadows are odd because they go in too many directions.
The big thing about 'backyards,' at least in the modern sense, is that they are cluttered. If there's no mess, then there's a walkway & a water feature, a picnic area, or a bunch of trees & bushes. So, try putting stuff in it!
Yes, the backyard will have a few more things in it. I need to figure out how to make the roof of the shed to appear to be slanted rather than flat. Any suggestions?
Ideally the whole thing will be repeated over and over again within a larger map area. This should be a small backyard for small animals like chickens or maybe a pig or a goat. Nothing too complex so it's more for a home kitchen garden and an out house.
Agreeing with everything that has been said. I would add that having the pen be the exact same width as the house looks odd. There's nothing wrong with doing it that way, I just don't like how that big house/pen rectangle looks. JT's trees break that rectangle up nicely, and another option would be to pull the shed to the left so it isn't inside the corner, but outside of it, again breaking up that rectangle.
My other constructive criticism is that while I really like the house roof, when I look closer I noticed that you forgot to flip over the tiles on the upper half of the roof. The tiles face upwards and rain will run into the house.