Alright, let's get to it. The first story we will be looking at is:
>Amongst her other plans, Aryanne finds herself participating in some neo-Equestrian obstetrics.
I would never have guessed that from the title.
Anyway, here we go.
>Luna’s moon finished its journey to the West, out of view, making way for its solar counterpart in Celestia’s sun to dawn a new day on Equestria.
This is a pretty eloquent opening line and I like it, but it's a bit too verbose. Using "Solar counterpart" along with "Celestia's sun" is extraneous, since one naturally suggests the other. I'd probably drop "solar counterpart" and just go with this:
>Luna’s moon finished its journey to the West, out of view, making way for Celestia’s sun to dawn a new day on Equestria.
Alternatively, you could do this:
>Luna’s moon finished its journey to the West, out of view, making way for its solar counterpart to dawn a new day on Equestria.
However, I think Luna's moon/Celestia's sun balances out a little better.
>Slowly, the gentle rays of light crept up on homes and through windows, stirring the ponies inside to wakefulness. Some ponies smiled, some frowned, some jumped out of bed, and yet others did their best to return to the realm of dreams. The ponies leisurely started their days, stovetop presses were primed with coffee, fillies and colts were awoken, and the little village of Ponyville started to bustle in tune with the other villages scattered over their peaceful world.
We're only a paragraph in, but the writing is actually pretty decent so far.
Anyway, there is some more description of the morning, and we gradually zoom in on a sleeping mare, who turns out to be a pregnant Aryanne.
>Her cutie-mark was now visible, a pink heart with an odd swirl of a symbol on it, common to her family and a few others, but otherwise unknown. She preferred to think it represented good fortune, family, and pride in one’s nation. Her friends sometimes called it “the windmill of friendship”, and she liked that interpretation as well.
I like this description of the cutie mark. Writing a character like Aryanne, who is basically just a ponification of a concept from the human world, into the canon world of Equestria can be a tricky matter. A symbol like a swastika, which would have no inherent meaning in Equestria is a good example of this; if a pony had the Windows logo or something as a cutie mark you'd run into the same trouble. This description is simple and believable, and fits Aryanne's character without requiring her to have any knowledge beyond what an Equestrian pony would have. Nicely done.
Anyway, Aryanne waxes philosophical on motherhood for a few more sentences, and then gets out of bed.
>Her hindleg left the mattress and blindly tried to find flooring, and she found herself straddling the mattress, with her large middle making further movement difficult.
You use "the mattress" twice in one sentence; it's better to avoid that sort of repetition. I've also noticed that while you basically write well, your sentences tend to run long. This sentence could probably be split into two sentences and streamlined.
>Her hindleg groped at the air, trying to find flooring. She found herself straddling the mattress, her large middle making further movement difficult.
This contains all the essential information found in the original, but it's a little easier to read, and avoids the repetition.
>Somewhat solitary, scanning shelf, she saw the article of clothing she needed to wear if she were to leave the house, a bra, lest she leave puddles of milk for some cats to drink.
This is very awkwardly worded. First of all, "somewhat solitary, scanning shelf" is an unpleasant alliteration. Second, it makes absolutely no sense. What does "scanning shelf" mean? Is she scanning a particular shelf? If so, there should probably be a "the" in there somewhere. Third, "somewhat solitary" makes little sense and is completely unnecessary to begin with. A person is either solitary or not solitary; there's no middle ground here. Arguably, since Ary is pregnant, you could probably hold a debate on whether or not the foal counts as a second person, but is this really the time and place to do this? Moreover, does her questionable level of solitude have anything to do with her scanning the shelf for a bra? Would this activity be somehow modified if there were another person around?
I'm assuming the implication is that Aryanne's crotch-boobies are swollen with milk, and she needs to don some sort of horse-bra in order to keep them from leaking all over the place. This is fine, but your wording really isn't the most elegant way of explaining the situation. You really ought to play around with this part.
>sans some sexy sire shenanigans.
The same issue with alliteration applies here, though I suspect it might have been intentional this time.
>bit the bra
>still somewhat sleepy
>pretty pregnant pony
>bound by bra
>All of the wiggling her rear began to remind her of the foal’s conception, and she was beginning to feel arousal build between her and the wall, but a proper mare didn’t start the day this way.
This information is erotic but unnecessary.
>provoking her progeny to prodding, perhaps playfully, she preferred to ponder, prodding in-turn to placate
Seriously, nigger; are you doing this on purpose just to annoy me?
Anyway, Ary puts on her horse-bra over the course of several paragraphs, and then goes out to her garden to get some breakfast. There is a bit of unnecessary explanation about Aryanne's garden being privately owned, as opposed to communal. Generosity is mentioned specifically, which may be some kind of dig at Rarity. I suspect this means that Ary and Rarity are involved in some kind of pony cat fight, and will slap each other and probably kiss at some point in the story. In any event, she loses her footing and falls down, which seems to irritate the foal in her belly.