Let's call this the obligatory self-insert story. Or whatever you want to call it.
I had this idea for a while and just wanted to write it down.

After getting Starswirl's journals, Twilight helps her daughter develop her time spells through the magic of friendship.

How and what specific lessons Starlight learns depends on how she tackles the challenges ahead of her.
(continuation of Daughter Starlight universe from season 6 onward)

After 1000 years, Nightmare Moon has returned!

Now she shall plunge the world in everlasting night! Plant life grows wildly, animals prowl the woods, soldiers are better trained and equipped, everyone can speak freely, eldritch horrors are destroyed on the spot, the economy takes an unexpected boom, and Equestria becomes an even more diverse and friendly place to be.

...Maybe we were wrong about Nightmare Moon the whole time?

sequel to How Starlight Glimmer Actually Reformed

Starlight Glimmer is now Twilight's daughter!
But how does this effect the elements of harmony and Equestria?
First thing's first, Twilight will have to tell her parents about their sudden granddaughter. Then they're going to have to talk to both princesses about the new legal princess who happens to be an ex-villain. Hopefully her brother and sister in law will understand. Then there's Twilight's friends, the town Starlight controlled, and many problems only the elements of harmony can handle.

Sometimes she wishes she could go back to the days where she raised a young filly, Starlight...

Princess Luna travels around Equestria delivering presents to good fillies and colts.

On her stop to Ponyville, four mares ask of her tradition and are eager to hear her story.

Based off of this Comic from doubleWbrothers
The beginning of the Daughter Starlight Timeline

Starlight Glimmer caused some troubling problems with Twilight and her friends. What past caused this pony to go down such a path? How did Twilight fix such a horrible past to make this pony better?

Check out the sequel

Based on Archemios stories
The_Republic and The_Empire

Set in a war between the Solar Empire and Lunar Republic.

Twilight, Rainbow, and Rarity have to live with their choice on siding with the Solar Empire. Are their decisions good for them? How do they know for sure? How does it effect the lives around them?

Fluttershy, Pinkie, and Applejack find peace in the Lunar Republic. They are still concerned about their families and hope they are doing their best. Will conflict stir when Discord threatens to finish them off for good? Is Luna starting to wonder if she did the right thing starting this Republic?

And what of the background ponies? How are their lives changed because of the side they chose?

It all leads down to the start of The War.

Applejack has lived a peaceful life on her farm. But everything changed when the lemon tree attacked.

Three Princesses look over genealogy papers. Except two are missing. Twilight's and Luna's.

After being defeated by Law, spirit of order, Discord scatters them to the farthest corners of Equestria.
Now the Elements must become stronger, learn new means of fighting, and turn into the heroes they were meant to be.

In the Western Ocean, Rainbow Dash becomes a pirate captain. Loyalty to her crew and her friends will be tested as she learns to command the wind. She will battle with swords and rifles. Most of all she will have to learn the history of the vast sea.

Up in the Crystal Mountains, Spike will grow and mature as he trains with a dying order of peace loving dragons. Temptations will present themselves to hinder Spike's dedication to his friends. One million scrolls is nothing for the scribe of Princess Twilight.

Far east, Pinkie Pie stumbles into a secret village. Her obnoxiousness might be the end of her. Will laughter be heard in the village of silence?

Sunset Shimmer never thought she'd return to Equestria. She was happy to be wrong. Now that a great evil threatens to take her home away from her, she must learn the power of her voice to find a place she belongs.

The unicorn kingdom is cold and cruel. A generous mare like Rarity will have trouble surviving the harsh tundra. Will the common folk be thankful enough to help her or will the vile nobles slam their iron hooves on them.

Fluttershy is happy to find a good friend in her time of need. However, when new laws pass that prevent her from aiding him and his family legally. Fluttershy will turn to nefarious means of profit.

When Zecora came to her village, Applejack was suspicious. She never trusted strange ponies from foreign lands. Now the tables have turned and Applejack has become a stranger in a strange land. She must learn to trust strangers if she wishes to return to her family and friends.

The Badlands. The place where exiles go. A harsh desert wasteland full of monsters and psychopaths. Twilight will be forced though many trials in this land. Will she keep her sanity or will madness claim her fragile mind.

In the end; Law must be defeated.