"But Mom!" Twilight Sparkle protested "Why do I need a foal-sitter!?"
"Because you're still very young Twilight and with Shining Armor going off to cadet training in just a few months you need to get used to us not being around and spending more time with Cadence" Twilight Velvet, Twilight's mother, replied.
"Well whoever this 'Cadence' is I don't want to meet her! I want to spend time reading books and learning magic so I can be the best at magic ever and earn my Cutie Mark! Not out playing with a grown mare twice my age!"
"Now, Twily" Shining Armor, Twilight's older brother, came into the room "I've met Cadence, she's a very nice pony who loves foals and she's the same age as me."
Twilight was getting a foal-sitter, which didn't seem very fair to her, she was a very grown up filly who could take care of herself, but her family didn't think that. And besides, why would they hire somepony to sit on her all day? That didn't sound very comfortable.
"Well does she have to come tonight?" Twilight began complaining again "I've only just heard about her and you're already leaving me alone with her, how do you know she's not one of those weirdo ponies who only get jobs as foal-sitters just so they can be alone with little foals?"
"Twilight, ponies like that don't live in Canterlot, and besides if in the unlikely event that Cadence is a 'weirdo pony' then you just have to go tell Mrs. Bridlestein next door and she'll try to contact us." Velvet replied
"But Mrs. Bridlestein would be more of a weirdo pony than Cadence anyway, I think she bit the mail-pony once."
A knock was heard at the front door.
"That must be her!" Crescent Moon, Twilight's father, galloped to the door to let the foal-sitter in.
Twilight went up to her bedroom as her father opened the door.
"Hello, Mr. Sparkle." Cadence greeted the stallion at the door and entered the house.
"Good evening, Cadence! Twilight's upstairs in her room, go up to her when you're ready." Velvet pointed a hoof at the door to Twilight's room, which could be seen from the bottom of the stairs.
"Ok, we'd better go!" Crescent announced "Cadence if anything happens we have some contact information on the fridge, if you can't get through Mrs. Bridlestein next door will be happy to help you. Twilight's bed-time is 9:30 and we'll be home at 11, take care, bye" Crescent, Velvet and Shining all left through the front door and Cadence waved to them as she closed the door.
Cadence decided that instead of calling Twilight, who obviously didn't want to see her, she'd go up to see her. Cadence trotted upstairs and slowly opened the door to Twilight's room.
Twilight was reading a book, in the dark, under a blanket, with only a light spell, which she had just perfected, as her source of light.
"Hey there" Cadence whispered loud enough for Twilight to hear her, the filly's silence working as a sign that she wanted Cadence to leave her alone.
"What'cha reading there kid?" Cadence approached.
Twilight rolled her eyes and replied sternly to Cadence "My name is Twilight!"
"Hmm, I've never heard of that book before" Cadence giggled at her own joke.
Twilight glared at Cadence, if looks could kill.
"Oh" Cadence pretended to realise that wasn't the name of the book "What'cha reading there, Twilight?" Cadence corrected her previous question.
Twilight giggled a bit but stopped after a few seconds. "Magical Compendium, Volume 1" Twilight showed Cadence the cover of her spellbook
"Oh, cool!" Cadence began "I've read that book before, I learned so many spells that I always use from it."
"That's impossible" Twilight corrected "There are only 2 copies of this book in Canterlot, I got this one from the library, the only other one in the whole city is located in the Castle Librar-"
Twilight stopped as she looked up at her foal-sitter for the very first time, noticing something about her that was extremly rare in ponies.
Cadence had a unicorn horn and a pair of pegasus wings
"Are you an alicorn?" Twilight asked
Cadence rolled her eyes, she always hated getting attention for being an alicorn ever since she earned her horn, she used to be a normal pegasus until she uncovered the power of love and used it to defeat a powerful enemy, since then she's been Princess Celestia's adopted niece, and a princess herself.
"Yeah, I guess" Cadence sighed
"Why do you seem so sad about it?" Twilight asked "I've always wanted to be an alicorn! But that'll probably never happen."
Cadence smiled "It's because everyone treats me like a princess, well, I am a princess, but It's like if anypony messes up and I see it I'll have a royal guard bring me their head on a silver platter."
Twilight continued reading her book. She turned to the next page and smiled as she found the spell she was looking for.
"Hey, I remember that spell!" Cadence gasped. It was a spell to make levitating heavy objects easier and take up less concentration and magic power.
"I want to try it out!" Twilight announced, determined to show Cadence how good she was at magic. She looked around the room for something to levitate with the spell.
Cadence nearly fainted as she watched Twilight's magic aura surround her bed.
"Woah there, kiddo!" Cadence cancelled out Twilight's magic with a special spell that only alicorn's can use.
"I know you're determined and all but instead of starting off with the heaviest thing you can find, you could try and get used to lifting objects that have varying weight."
Twilight whimpered as Cadence went over to Twilight's toy box to find the lightest toy she could find, she dove her head in and eventually came back out, holding a small rag doll in her mouth.
"No!" Twilight levitated the doll with so much strength she nearly pulled her foal-sitter with it. "Smarty Pants is my favorite doll in the whole wide wide world of Equestria! There is no way I am letting you do tests on her!"
"Um, Twilight, you're levitating Smarty Pants right now" Cadence pointed out
Twilight shrieked as she dropped Smarty Pants on the ground "Smarty Pants! I'm so sorry for doing magic tests on you! Are you ok?"
"Maybe spellbooks are more of a day-time thing" Cadence decided, she looked at the clock and realised it was Twilight's bed-time.
"Well, it looks like It's time for bed, Twilight!" Cadence announced as she walked over to the bookcase to find herself a story to read Twilight in bed.
Twilight climbed into her bed.
"Spellbook, Spellbook, Textbook, Reference Guide, I see ponies twice my age reading this book!" Cadence couldn't find any story-books in Twilight's mini-library, but then she found something that even she had read before.
Daring Do and the Quest for the Sapphire Stone
"Hey, Daring Do! I used to read these books all the time when I was little!" Cadence levitated the book from the bookcase and went over to Twilight's bed, as she went to sit down on it Twilight scooted away and whimpered.
"What's wrong? I'm only gonna read you a story" Cadence asked
"P-please don't sit on me." Twilight begged
Cadence started to giggle "Twilight, a foal-sitter isn't somepony who actually sits on little fillies and colts, a foal-sitter is a pony who takes care of a little foal when their parents can't, they'll always be there for the foal when they're needed, and sometimes be like their big brother or sister."
Twilight looked at Cadence with a glimmer in her eyes. "Well, I already have a big brother, so... w-will you be my big sister, Cadence?"
Cadence smiled and hugged Twilight "Of course I will."
Cadence spent the next half-hour reading the story to Twilight, eventually she fell asleep, Cadence closed the book, put it away, turned off the light and left Twilight to sleep in peace.
About and hour later Twilight's parents and Shining Armor arrived home. Velvet went upstairs to check on Twilight. Crescent went to take off his suit and Shining stayed to talk to Cadence.
"So, how did it go? Was she a challenge?" The colt asked.
"At first she didn't really want me here, but after I helped her with some magic we started getting along. After that I read her a story and explained to her what a foal-sitter is. She asked me if I would be her big sister since she already has a brother, so I guess we're related now" Cadence giggled at her last few words.
"Well," Shining began "If we're 'brother and sister' as Twilight's making things now. I don't think we'd be allowed do this." Shining Armor gave Cadence a gentle peck on the lips, making the pink alicorn blush.
"Cadence! You're amazing! We've never been able to get Twilight to bed at her bed-time nevermind have her asleep at this hour. I think we'll have to make you our go-to sitter." Velvet payed Cadence and the alicorn wished the family a good night and departed back to the castle.
Cadence smiled to herself, knowing that from now on, Twilight could be the little sister she'd always dreamed of.