When Celestia has a child, the least Equestria is worried about is who the father was, it is why her child is blind. Luna's child is star-struck and Discord's child is the opposite of her father.
Celestia's child is a long-awaited thing, something that would only have happened if Celestia's rule was weakening. But Baby Tia is different to her mother in more than just a cutie mark.
Luna's child is a suprise, but she is focused on the stars when discord reigns below.
Princess Celestia held her child with her magic as she stepped out of the room to present her to the other Princesses. Twilight, Cadance and Luna looked beautiful in their crowns, horseshoes and gowns. Cadance immediately rushed over to Celestia holding Flurryheart, still a filly.
'She's beautiful. But she looks so different to you?' said Cadance, worried.
'What colour are her eyes?' asked Luna. 'Are they blue, or pink, or, or, I don't know, yellow?'
Celestia shied away from Luna.
'Actually, they are, um, white.' she said, obviously nervous.
'WHITE!!!' everybody cried, astonished.
'She's blind.' Celestia explained. 'Too much sunlight.'
'I knew that stuff was bad for you!' cried Luna exultantly.
'What? was it something I said?' Luna said to the frowns.
Baby Celestia Dawn, or Tia was born blind, but she could see as long as there was light. Something about her sucked up the light and gave her an awareness of where things were. It was for this reason that there was always a light in her room. Without it, she was truly blind. but Tia gave off her own light as well. Just not at night. Celestia was constantly hassled with the chores of raising a normal baby, but made a tiny bit harder in the fact that Tia would never learn to read, write or know her mother's face.
'Mama, where be you? Mama, I not know where you be!' The baby's cries echoed through the empty halls of Canterlot Castle. The sound of hooves shattered the silence that followed.
'Mama, be you come? Mama, are you come? Mama, be you here? Where be you Mama?' The hooves were closer now.
'There you are, Celestia Dawn!' came Luna's voice.
'Auntie Woona! Where be Mama? Where be Tilight and Shiny and Cadnce? Where be Mama?' cried Tia.
'Celestia Dawn. Shush. Listen to me. Mama is away, and I am looking after you, although in my state I'm not sure why. This means that you don't go wandering off, and that you need to pay attention. Now listen. Luna is here to protect you, so you come with Auntie, Please Tia?' Luna hushed the baby and used her magic to place Tia on her back.
Baby Tia struggled, batting her wings and trying to get out of her aunt's magical grasp.
'Now now Tia. You must be good for me. Now please be quiet and hold on, I am just going to raise the moon. Please stay still.'
And with that, Luna beat her wings and raised herself up, her horn glowing. The moon came up, just as the Sun went down.
Tia cried as she lost what little sight she had.
The only sound in the room was that of scritching pens. Only one, but to Celestia Dawn, it sounded like more.
'Is this OK?' came the voice of a spiky dragon.
'My name is Celestia Dawn. I am three years old. I have just learned to walk. I can talk, but I can't write. I can't look at pictures. And I will never, never know my mother's face. I was named for my mother and the start of the day that she brings about. I am blind. Spike says he is a Dragon, but what is a dragon. All I know is he is sitting to the left of me, Mum on the right and Twilight in front of me. Mum is tall for a pony and Spike is small for a dragon. Mum, Twilight and me are alicorns. That means we have horns and wings. Not that I will ever use mine. I'm blind. I can't see, so I don't know where to fly, I can't see so I won't know where to put my magic, I can't see, I can't see. That's all everypony thinks, except the princesses and Twilight's friends. Mum says don't worry about it, but what else is there for me to do.'
Luna came out of the room looking at the tiny deep blue filly wrapped in her magic.
'Luna Dusk' she said hoarsely as Pinkie Pie bounced up.
'SHE'S ADORABLE!!!!!!!!!!!!!!!!!!!' squealed Pinkie. A purple-lined zipper appeared on her mouth, holding back whatever she was going to say next.
'Is she, um, like Celesta Dawn?' asked Twilight nervously.
'No, she's perfect!' said Luna. 'Except...'
'WHAT' asked everybody in the room, curious.
'She is Nightmare Moon.' Luna fell to the floor in a faint as everypony looked around.
'She must be joking.' said Celestia flatly. 'I'll take her up to her room.'
Luna Dusk was a perfect little filly, the mirror image of Celestia Dawn.
They grew up together in the grand empty halls of Canterlot castle.
Lulu and Tia loved to go to their aunt Cadance's castle. Although it was far away from their mothers, it felt like a real home to them, as did Twilight Sparkle's castle. Their cousin Flurryheart was always delighted to see them, as were Twilight's friends.
Lulu, Tia and Flo, or Luna Dusk, Celestia Dawn and Flurryheart, were best friends but they were all afraid of Lulu's mum, Princess Luna.
Princess Luna had not gotten over the fact that her child looked so much like Nightmare Moon, and so refused to see her child. When she did, there were tense silences, eventually broken by Luna muttering 'Go to your room child.'
One day Lulu and Tia were exploring Twilight's castle and they came across a darkened hallway. Tia walked in, letting off a soft glow from her fur.
'Tia, don't go in there, we don't know what's in it!' cried Lulu, as she edged forward into the corridor.
'I never know where things are anyway. I'm blind, remember!' replied Tia.
'Oh, wow.' breathed Lulu as they came out into a wide open room.
'What is it Lulu! What can you see! Oh please, please tell me!' Tia cried, turning her head every-which-way, trying to understand what she had just walked into.
'Oh ho ho ho oh! I have a child I have a child!' a draconequus danced around the shape of a filly forming in the air out of rainbows pumped in by a strange contraption that was sucking up the colours in a painting.
The finishing touches were put onto the pony and it stepped out of the cloud of colours. The filly looked at her creator and cantered over to give Discord a hug.
'Dad.' she whispered. Discord smiled broadly. So broadly in fact that he plucked off his mouth and put it on the painting as he hugged the pony back.
The filly had rainbow-coloured eyes, a purplish-blue coat and a pink mane.
3 years later, Discord was trying to get his daughter to be at least a little bit chaotic.
' Stormcloud, please, please get your room messy!' he begged Stormcloud.
Stormcloud's eyes became black and then she opened her mouth and threw lightning bolts at Discord.
'Hey, stop that! Actually good job, Storm!' Discord cried, for once glad that his daughter had created at least some chaos.
Stormcloud ran out of the chaotic castle, fleeing her father, fleeing everything she had ever known.
She came across a cream coloured filly with a golden mane in the midst of a chaos-storm created by Discord.
Stormcloud was shocked, and so she ran into the storm, her magic making everything orderly for a moment as she went through.
She grabbed the filly and teleported them far, far away from Discord, all the way to the Great Hall of Canterlot castle.
Princess Celestia gasped as she saw her daughter magically appear with a stranger, who seemed to have teleported them there.
She ended the meeting and rushed over to her child, gently pushing the stranger aside.
Tia heard her mother's voice as she slowly became conscious. She began to give off the golden glow that she used to sense when other ponies were nearby. She didn't need it for her mother though, she could feel her magic.
'Mother? Where am I? Am I home? Who was that?' Celestia Dawn spoke softly, uncertain of her surroundings, her light wasn't bright enough.
Stormcloud stared in amazement as she saw that the young filly she had rescued from the chaos-storm was blind. What was more, she was the daughter of Princess Celestia herself!
'Mum, where's Auntie Luna? Where's Lulu and Flo? Where's Caidy and Shiny, Where's Twily? Who brought me here?' the flood of questions was held up by a golden sheath of magic on the cream coloured filly's mouth.
'wait. I have to check. Twily's in her castle, Lulu and Flo are with her. Caidy and Shiny are in the Crystal Empire, and Auntie Luna is in her twoer. As for who brought you here, I have no idea. All I know is that she teleported you here from the Everfree Forest. And WHY were you in there in the first place?' Celestia answered Tia's questions and asked her a question of her own.
'I don't know! I just want to go to my tower!' said Tia, whining.
'Umm, maybe I should take Celestia Dawn to her friends?' asked Stormcloud once she had the full picture.
'OK. Once you answer my question' agreed Celestia.
'Uh, sure!' replied Stormcloud.
'Who are you, and where did you find Tia?' Asked Celestia in a loud voice.
Stormcloud shrunk back, then spoke.
'My name is Stormcloud, or Stormy. I found Celestia Dawn in the middle of one of my father's Chaos-storms.'
'Wait. Your father is DISCORD!' cried Celestia.
A golden cage was suddenly placed around Stormy.
'Wait, what!' cried Stormy. 'I don't meant to hurt anybody!'
'Give me one reason to trust you!' cried Celestia fearfully.