Here’s a list of Cinder and Thorne being full on siblings throughout the series in no particular order:
Thorne scoffed. “Careful is my middle name. Right after Suave and Daring.” “Do you even know what you're saying half the time?” asked Cinder.
“Did you see any rice in there? Maybe we could fill Cinder's head with it.” Everyone stared at him. “You know, to...absorb the moisture, or something. Isn't that a thing?” “We're not putting rice in my head.”
I passed out from stress? That’s it?” “I believe the princess term is fainted,” said Thorne.
A relieved grin filled up Thorne’s face. “We’re having another moment, aren’t we?” “If by a moment, you mean me not wanting to strangle you for the first time since we met, then I guess we are.
“A captain always knows where his ship is. It's like a psychic bond.” “If only we had a captain here.”
“But I'm a wanted fugitive, like Cinder.” Thorne continued. “They do realise I'm missing, don't they?” “Maybe they're grateful,” Cinder muttered.
Thorne, on the aisle, held out his hand as Cinder passed. She snorted and accepted the high five before floating up the stairs.
“I hate to agree with Thorne,” said Cinder, “I mean, I really hate to agree with him, but he's right.”
“Wherarewe?” Thorne muttered. “Oh, you’re awake already,” said Cinder, returning with salve and gauze. “I was hoping you’d stay knocked out awhile longer. The peace and quiet was a pleasant change.”
“At least we have each other.” He held out his arms, like he would have given her a huge hug if they hadn't been strapped into their seats. The nose of the ship tipped to the right and he quickly grasped the controls again, leveling it out just in time to dodge flock of pigeons.
“Honestly, Thorne.” A girl. Linh Cinder? “Do you ever think before you speak?” “What? What did I say?” “ ‘Is that all hair?’ ” “Did you see it? It was like a cross between a magpie nest and ball of yarn after it's been mauled by a cheetah.” A beat. Then, “A cheetah?” “It was the first big cat that came to mind.”
“Let's pick it up,” the man behind her said. “How many more of the tranquilizers do you have?” “Just three,” the girl panted. “Gonna have to restock.” “Right. I’ll just... head down... to the convenience store, and-“ she didn't finish, the strain too much.
“Wh—what are you—how? Where have you been? What’s going on? Why are you wearing that stupid bandanna?” He laughed. Gripping a wooden cane, he stumbled toward her, waving one hand until it landed on her shoulder. Then he was hugging her, suffocating her against his chest. “I missed you too.” “You jerk,” she hissed, even as she returned the hug. “We thought you were dead!” “Oh, please. It’d take a lot more than a satellite plummeting to Earth to kill me.”
“We should take her with us.” Cinder glared. "”Are you crazy?” “Crazy in love. She's gorgeous.” “You're an idiot. Help me carry her to the living room.”
“I promise not to make fun of your boyfriend anymore.” “He's not my boyfriend!”
Thorne blinked at her, then down at the sewage he could barely make out in the darkness. “Don't you have some tool in that fancy hand of yours that can get us across?” Cinder glared, light-headed from her body's instinctively short breaths. “Oh, wow, how could I have forgotten about my grappling hook?”
