Undertale AU Sibling Oneshots

Toriel x Older Brother! Reader

(Hope I did well! Mini AU where Azzy and Chara didn't die. Azzy was born later on, and Chara fell with Frisk! Tori and Asgore are still together because I prefer to ship them, and you all live in the palace still!)
Requested by the lovely corvid @averyiconicuser! (Sadly can't tag still, slow data sucks as—)

You quickly gave your sister a side hug before you left her to her baking in the kitchen. It was nearing the holidays, and she loved to bake so many sweets for friends and family. (My mom does this too if she can! She also creates cookie trays to sell around Christmas time)
So while Toriel was baking, you moved to entertain her children in the living room. Asgore was out doing his rounds and meetings of being King, so as Duke and the next in line to be babysitter, you were tasked with watching Frisk, Chara, and Asriel. (Hi again, asked my mom about this one, so since you're Toriel's brother, you would be considered a Duke or Earl in nobility rank!)
"Playing nicely, you three?" You asked softly, coming up to sit with them.
"Yep!" Frisk replied, moving a small pile of edge puzzle pieces to Asriel for him to put together. You watched as Frisk and Chara took over with the middle pieces, putting them together whenever they saw a match.
You quietly reached out to help them, and once it was done, you helped them move it onto a board and set it on a table for the King and Queen to see later.
"Is mom done baking yet?" Chara asked, glancing towards the kitchen, clearly trying not to drool.
You chuckled. "Not yet, let's go pass some more time in garden."
You led them through the palace, guiding them out to the garden. You discreetly kept them away from the buttercups, knowing what happened to Asgore, instead guiding them to the patches of purple and blue flowers.
"Do you see this kind of flower?" You asked softly, crouching and gesturing to one of the softly glowing blue flowers. "It's an Echo Flower."
"What's that?" Asriel asked, the children coming up to get a closer look.
You smiled at him, leaning into the flower to whisper something before backing away, letting them get close to listen.
'Hi! I'm an Echo Flower! I repeat things!'
The delight and awe on their faces was a treat to see, the flower echoing your voice a few times before fading.
"Here," you reached out and picked three of the Echo Flowers, passing one to each of them, "Whisper something and then let's go show your mother."
They each whispered something into their flowers, following you back towards the kitchen afterwards.
"Toriel?" You called, smiling at the sound of the children's giggles.
"Yes, (Y/n)?" She replied, having just finished cutting a freshly cooled pie.
"The children want to show you something." You watched as the three slipped out from behind you, trotting up to their mother with Echo Flowers in hand.
"Oh! How sweet!" She gasped happily, crouching down.
"They whisper things said to them!"
"We each said something special too!"
Toriel's expression filled with warmth and joy as she took each flower from them, reaching out to hug each of her children at once.
"Why don't we have some pie?" Toriel asked after a moment, standing back up and turning to the pie on the counter.
"What about dad?" Frisk asked, letting you pick them up and carry to the table.
"He's unfortunately stuck in royal business for most of the day, so he said that he'll have pie later, dears."
With that, you all settled at the table for pie. Asgore showed up late afternoon, and after another round of pie with him, you, Asgore, and your sister all tucked in the children.
As you entered your room to go to bed, you found an Echo Flower resting on your pillow.
Smiling, you picked it up, listening as the sound of your sister's voice.
'Thank you for being such a great brother, (Y/n).'