There's another series involving Spinel content.
BTW, this takes place before the movie, but Steven is 16 in this.
"Pearl?"
The pale Gem looked over to him, lowering the book she was reading, "Hm? What is it, Steven?"
Steven placed a hand on his forehead while looking at the other, "I don't know why, but while I was napping, I had this weird dream where I was standing in some kind of dirty, withered garden floating in space."
Pearl's eyes went wide as moons, "... A garden in space...?"
"Yeah," said Steven, "And then I turned around to see this tiny pink shape a distance away from me-"
"OH MY STARS!" Pearl stood up fast, sounding panicked, "Could she still be there?!"
Steven became worried, wondering if telling her about his dream was a good idea, "U-Uh, Pearl-"
"How could I have been so forgetful?!" Pearl walked over to the warp pad, looking over to Steven, "Come on."
"W-Where?"
"To your mother's garden."
The Garden
Upon arriving there, Pearl and Steven looked around, the former gasping at the sight. The Garden, once beautiful and lively, was now bleak, quiet and dead. The stars hung above them, delivering no wonder or awe. Dying grass grew through the cracks and the pillars has broken into pieces, still floating. It was a horrible sight.
"Oh stars..." Pearl breathed, cupping a hand to her mouth.
"This was Pink Diamond's garden?" Steven asked her, disbelieved.
The pale Gem nodded, "Y-Yes. It didn't look like this before-"
A yip was heard.
The two heroes turned their heads to see what was awaiting from them. Steven was more shocked than Pearl was.
It was... a dog! A tiny dog, staring right at them with big, confused and scared black eyes. Roots were tied to its paws and poofy tail. Its fur matted with grime and bags hung under its eyes.
Steven never saw a dog look that pathetic.
Acting on instinct, the boy ran over to help the poor thing, but it ended up scaring the dog enough to make it yap at him in defense. Steven stopped a few inches away from it. Then the dog whimpered and hung it head shamefully.
"H-Hey," Steven took the gentle approach, "It's okay. We're not to hurt you. Here, let me help." He carefully tore the roots off its paws. It was by then he saw the dull pink colors of the dog and the heart-shaped gemstone nested in the center of the white, fluffy fur on its neck. It was a Gem. Well, a Gem-dog, to dub it.
"Oh Spinel..." Pearl gasped, "Did Pink really leave you here?"
Steven whipped his head around to stare at her, "W-Wait?"
Still trying to get over her own shock, Pearl told Steven what happened from what she could remember. While the Diamonds were investigating Earth, they saw how the humans used dogs for several purposes, but they saw how humans and dogs bonded and thought it would be a wonderful gift for Pink Diamond. They created a Gem-dog named Spinel, and for a while, Pink loved her new gift.
Until the day Pink received her colony, she told Spinel to "stay" and left. Pearl did ask her Diamond about that, but all she was told was "not to worry about her".
"S-So..." Steven was trembling a bit, "Mom just left her here?"
Pearl nodded solemnly.
Gritting his teeth, the teen picked up the Gem-dog and held her up, "Don't you worry, Spinel. You don't have to wait any longer, you have us now."
Spinel blinked in surprise, and began to pant and wag her heart-shaped tail excitedly, leaning her head to lick his cheek. Steven laughed from the affectionate gesture when the pale Gem tapped his shoulder.
"Let's go. We shouldn't make her stay here any longer."
Steven couldn't agree more.
"Alright, Spinel!" Steven announced as soon as they arrived home, "Welcome to the Beach House! Feel free to explore." He placed Spinel down, expecting her to be very eager to look around.
Except she wasn't.
She was sniffing around, her flopped ears perked up in curiosity of the new environment, but she looked over to Steven and whined, confused by what she was supposed to do.
"Hm..." Pearl put a hand to her chin, "I don't think we should let her wander around the house in a... dirty state. "
"U-Uh, right!" Steven realized, "Let's give her a bath!" Picking up Spinel, he and Pearl headed into the bathroom.
They filled the tub with warm water, despite Gems not feeling the temperature, and Steven called her over. Spinel peeked over the edge to the water, and in an act of silliness, she hopped into the water, splashing Steven. He laughed it off and went to dry himself off. Spinel was panting happily, liking the feel of the water soaking her grimy fur.
"Alright Spinel," Pearl picked up the bar of soap, "Let's get you all cleaned up."
However, Spinel's happy mood dropped when Pearl got close. As soon as the pale Gem got too close for the Gem-dog's comfort, her expression contorted to that of anger and began to growl and bark viciously, her eyelashes upside down. Despite her fur being wet, it fluffed up to make her look bigger as she made Pearl fall back as she barked senselessly and furiously.
Steven panicked, "W-Whoa! Whoa whoa whoa!" He ran over to the tub, Pearl backing away, "S-Spinel! Calm down!"
As if a switch was flipped, Spinel stopped, her anger fading into joy as she looked happily at Steven, her fur lying flat and tail wagging. Pearl got up, baffled by what Spinel just did.
"Stars..." Pearl said through her breath, "Guess she doesn't like me."
Spinel turned to her and growled, Steven eased it by petting the back of her head. "U-Uh Pearl, I don't need to be rude but-"
"No, it's fine," The pale Gem stood up, "I'll leave if she doesn't want me here." And left and closed the door behind her.
Steven was worried he hurt her feelings, and sighed while Spinel looked more happier that the other Gem was gone.
"Oh Spinel, what are gonna do with you?" He said, before grabbing the soap and cleaned Spinel himself. It wasn't too hard to get all the grime from her wait in that cursed place, but the hardest part was to get her still. As the Gem-dog saw her fur getting cleaner and cleaner by the second, she got very excited and tried to wriggle herself out of his hand that held her belly up. And Steven laughed when Spinel tried to eat the soap bubbles.
Once that was done, Steven rinsed her off, revealing the hot pink, pale pink, and white colors of her soft fur. He drained the water out of the tub and went to grab a towel, but Spinel hopped out of the bathtub and shook the water out of her pelt. Steven yelped and covered himself up with the towel as water droplets sprayed everywhere.
"Hey!" Steven laughed.
Spinel yipped cheerfully as her fur fluffed up, making her neck fluff almost swallow her head, her poofy tail wagging. Rolling his eyes in a more friendly manner, Steven grabbed the comb he still hadn't used and brushed through her fur. That turned out to be surprisingly easy, no tangles whatsoever. Spinel even enjoyed it, leaning into the comb as it smoothed her fur out.
And there stood a new Gem-dog; bright and colorful, clean and dry, and as happy as it could be.
Spinel stared down her body, opening her mouth to pant happily, setting her paws on his chest and licking his cheek. Steven chuckled from that, petting her neck fluff before picking her up as she continued to pant and wag her tail.
"Well Spinel," Steven smiles to the dog, "Welcome to your new home."