Prince of the Sun and the Moon and Co-ruler of Equestria, the first child of Queen Twilight Sparkle and Prince Flash Sentry of Equestria. He was the second ever born alicorn after Flurry Heart and proved that you don't need to earn being an alicorn and it can be passed on genetically.
Being the first child of Equestria's leaders is no easy business. He felt like he was held up to a higher a standard since a young age even though his parents weren't that strict. He would isolate himself and study just like Twilight did when she was younger. Solar was a huge mommy's boy and had always wanted to be a leader like his mother. Of course, he was forced to socialize, but he took a rather manipulative take on his friendships, but Twilight never found out so i can see this is an absolute win.
He earned his cutie mark in his early teens, when he discovered his magic was powerful enough to control the sun and the moon, since then Twilight has taken to teaching him how to do it. He was officially crowned at 18.
Solaris took a lot of things on his own as a child, which made him believe he was better than everyone else. He has never talked to anypony about his hardships and insecurities, so he is bubbling with negative emotions on the inside, but his cold exterior hides it rather well. A lot of ponies question whether he is a good ruler or not. Solar is kind of a controller, rather than a friendly leader like Twilight. He finds his mother's ruler style reckless and he often blames her for all the bad things that happen, although he rarely tells her that. He wants a good image in his mother's eyes, so she doesn't take away his prince privileges all of the sudden.
Princess Summer Sunset
Since she was the second child and a pegasus, Summer never felt that she had to hold herself to a high regard like her brother. She was really close with her father, who'd take her to hang out with other royal guards, which lead to Summer Sunset not really being interested in all of that princess business. Well, this also lead to some situations when some rather perverted stallions tried to take advantage of the young filly, however, Flash made sure no one touched his little filly. No one, right? Hopefully, there wasn't an event in her backstory that dramatically effected her sexuality. Since a young age Summer didn't like feel she belonged in Canterlot. All those fancy-talking aristocrats were just too much for her free spirit, so she spend the majority of her late childhood and late teens traveling the world. She eventually got her cutie mark in Seaquestria, when she mastered a technique that let her swim with her wings. Of course she settled back in home town after she got tired.
Summer Sunset is really chill and has a cool big sister energy. She is a bit more on the extroverted side even though she does value her alone time. She was spoiled by her parents when she was little, which lead her to being a bit irresponsible in her adult life, but luckily all that traveling forced her to learn to be more independent and mature.
Twilight knew Canterlot life wasn't for her oldest daughter and since her old castle in Ponyville remained unoccupied she asked her if she wanted it. Summy agreed, and soon our rocker lesbian pegasus moved in with her two little sisters.
Princess Cloudy Nightfall
You'd expect the daughter of the ruler of Equestria to have powerful magic or at least be one of the most talented like her mother once was. This isn't the case here. In fact, Cloudy Nightfall over here has below average magical abilities. This doesn't stop her from being a try-hard and a total nerd. Cloudy has always idolized her mother and the rest of the Elements of Harmony, so she would do anything to live the life her mother once had. She is really hard working and always finds time to practice her magic, however, she doesn't neglect her social life. She goes out of her way to befriend ponies, despite being introverted, but that is not the cause of her loneliness. She doesn't make friends, for the sake of making them, but rather, because this is what her mother did to be successful. She is really awkward, clingy and her presence overall makes ponies uncomfortable. It doesn't help she lacks self-awareness in most situations, so she remains confused when her ''friends'' leave her, despite her being very supportive and optimistic. Cloudy is a nervous wreck, she constantly has something to worry about, which often causes her to speak quickly and/or shake violently. Twilight tries to remind her not to push herself that hard and to relax, but her daughter just never listens.
When Nightfall heard her older sister was moving to Ponyville, she quickly jumped at the opportunity and asked if she could come along. Living in the town, where the Elements of Harmony had basically formed was like a dream come true and so, Cloudy along with her older and younger sister moved to their new home.
Princess Ancient Abbigail Magic Sentry or simply Abbigail
Here's a real doozy for y'all. During her 4th pregnancy Queen Twilight experienced a lot of magic shines coming from her belly, which made her believe they were having an alicorn again or a really powerful unicorn, so her and Flash started thinking of magical names. It really hit them by surprise when their daughter turned out to be a grey earth pony. Despite that, they still gave her their chosen name to prove that earth ponies weren't less valuable. However to them, she was a simple magicless earth pony and nothing more until she started getting outbursts, the likes nopony had seen before. Heck, Twilight and Flash had to take care of an alicorn before and even his magical outbursts weren't that powerful. Luckily, Twilight found a spell that deactivated her daughter's magic and life continued on as normal.
Abbigail has always hated her birth name. ''Ancient Magic'' as if she is supposed to be some all-powerful alicorn or a unicorn very well educated on the history of magic, so she prefers to be called by her middle name. She has always seen herself as a burden on her family. Out of a family of colorful, magical royal figures she gets to be the depressingly colored earth princess. She has expressed her feelings to her family ,however, after constantly getting the same response of ''you're not a burden'', carelessly thrown at her, she gave up in looking for encouragement. When she was younger she had more hope. She hoped she could prove herself as a worthy member of the royal family. She even started studying magic, which seemed to actually be very easy for her. She even thought she could use magic, because she saw it in what her mother told her was just a strange dream (spoiler alert: Abbigail CAN actually use magic, but her parents are trying to keep her away from it, because even they don't understand her power). Since then Twilight has actively discouraged her daughter from learning magic.
Abby had a rather depressing childhood, despite living in a fancy castle. She always saw herself as a small bug in the large building that was the Canterlot Palace. She rarely left the boundaries of the castle since everything she has ever needed is already there for her. She grew bored with life really quickly and her social anxiety didn't help. The everyday boredom of having to do absolutely nothing all day is slowly killing Abbigail's sanity. Little things don't excite her anymore. She can rarely feel dopamine rush to her brain. She once slit her wrist just, because ''she wanted to see the blood'' and the master chef was terrified when he found the little princess in the kitchen with a knife and a bleeding wrist. Even more terrifying was her trembling smile, despite her clearly being in pain. Her parents took measures she never did that again. Well, ''took measures'' sounds kinda harsh, considering they forgot about the problem like a week after it happened.
Abby's only ''friend'' is her older sister, Cloudy Nightfall. The two of them share the insecurity that they might be worthless, but Cloudy is the more optimistic one and tries to remind her little sister that things will become better one day. Abbigail likes to entertain the thought that she will be happy one day, but the doesn't see how it would happen.
She was inevitably forced by her Cloudy to move to Ponyville with her and their older sister, Summer Sunset. Abby didn't think much of the change at first, but she quite like the fact that she was no longer in the bustling city and enjoys the beauty of the Ponyvillian county side.
Both Abbigail and Cloudy go to the School of Friendship.