So it's just as the prompt says except for where Cora has her heart. Sorry, somehow I missed that part when I read it.
Title – Punishment Fit For Queen
Prompt requested by EvilQueensDaughterRaunzel - Well I had an idea about Henry Sr. being gone on a trip and a twelve year old Regina being left alone with Cora. Cora always seemed to have a certain kind of hate for her daughter's long hair that goes almost down to her feet. Regina goes to play with Daniel in the stables although Cora told her to stay in the castle. Cora sees them playing in the hay and is furious. She drags Regina to her room and calls a servant to bring her scissors and a razor blade. She cuts Regina's long braid and throws it into the fireplace and lets Regina watch it burn before she shave her bald. When Henry gets back he isn't happy about it. In Storybrooke Cora has her heart back and wants to apology for her actions and regrows her daughter's hair so that it goes almost to her knees.
Setting – 2x12 after the car scene with Cora and Regina
Her mother was back. She lost her son. So she let herself be manipulated by her mother. She should have known better and resisted the pull of darkness Cora so easily influenced.
That night she let her mother back into her heart knowing full well how dangerous it could be. Thing was she couldn't bring herself to care. Her heart had already been broken.
She stood in her bathroom, facing the mirror and taking in her tired features. Her eyes were tired with dark circles and her skin was pale from hiding out. The girl that stared back at her was nothing like the woman she once was. A hand was suddenly on her shoulder and she winced, meeting Cora's eyes in the mirror.
"I missed you darling. And I really want to be better for you," she said, combing her fingers through short dark locks. Regina shuddered, the memory flashing all too quick in her mind.
She was twelve at the time of the "incident" and she remembered it like it was yesterday. Her mother always seemed to be obsessed with touching her silky locks even when she was a child.
Her mother had hired a new stable boy. He was a year older than her but still acted like a child and when his work was done they'd go play in the fields or the stables. Her long dark hair flowed down her back. Mother liked it long and styled but Regina preferred it to fly loose when she ran.
One day her father had gone out of town for a few days, leaving Regina alone with Cora. He was worried. Cora was often abusive and hard on their daughter and it worried him that he wouldn't be there if anything were to happen.
After her lessons she ran out to play with Daniel after her mother specifically told her to stay indoors. She thought maybe she could sneak out for a few minutes while Cora was busy in her study taking care of the usual finances for the estate. It wasn't until she looked out the window did she see Regina running around with that stable boy, her long beautiful hair flowing all the way down her back.
Fuming with rage Cora stormed out of the estate and out in to the fields where Regina and Daniel were playing. Regina stopped chasing Daniel and froze in her place when she saw her mother angrily stalking up to her.
"Mother?" she asked, her face shaking in fear and she cried out in pain when Cora grabbed her arm and yanked her towards her.
"I did not give you permission to be outside and run around like some peasant!" she yelled before turning her steely gaze to Daniel. "Leave! Now!" she snapped and the child ran for the stables.
"Mother! Please stop," she cried as Cora dragged her into the house and pushed her down on the floor in front of the fireplace.
"Proper ladies don't run around like filthy commoners and ladies don't run around with their hair flying in the wind!" she snapped, grabbing the scissors and holding Regina down as she cut through long dark locks until it was gone. Regina cried and tried to get free but her grip was tight, bruising her skin. All she could do was watch her hair fall to the floor in heaps. And then with a wave of her hand, Cora sent the dark locks of hair into the fire and Regina watched horrified as they burned.
When it was over Cora locked Regina in her room for three days until her father came home. He never stood up to his wife but the moment he saw Regina's bald head, he lost it.
"How dare you cut her hair!" he yelled, storming into her study and Cora looked up from her book. Her eyes flashed dangerously at the audacity of him speaking to her like that. "Cora, she is just a child!"
"A child that must learn! She's not a little girl anymore and I must teach her to behave even if I must traumatize her to make the lesson stick!"
"What you did was cruel!" he yelled but then his lungs were suddenly screaming for air and he felt himself being raised in the air. His hands clawed at the invisible force around his throat.
"I'll punish Regina the way I see fit and you have no say in it. Must I remind you what happens when you go against me?" she asked and he managed a small nod.
"Good," she said and dropped him to the ground and he gasped for air. When she was gone he went into Regina's room and his heart broke at the sight of his 12 year old daughter crying silently on her bed. He sat beside her, soothingly rubbing her back.
"I'm sorry honey," he whispered.
"Why does she hate me?" she asked, her voice trembling and heavy with tears.
"She only wants what's best for you sweetheart."
"But she cut my hair because I was playing outside!" she protested in disbelief and sat up, hugging her father and breaking down in sobs. He held her, his hand cradling her head and wishing he could be stronger for her.
Regina shook her head from the memory and stepped away from Cora. "Don't touch my hair," she said, her eyes distrustful. Recognition flashed across Cora's face and she was suddenly realizing why Regina was touchy when it came to her touching her hair.
"Let me be better for you," she said again and with a wave of her hand Regina's hair grew down her back and Regina gasped in surprise.
"What are you… Mother," she stammered, not knowing what to say and she reached out, placing her hand on her daughter's cheek and then pushing long dark hair behind her ear.
"I'm sorry," she whispered and Regina just stared at her, not knowing whether this was some kind of trick or if this was really genuine. She didn't know if she could still trust her. She wanted to though. All she really wanted was her mother's love.
"Ok," she nodded and Cora hugged her, cradling her daughter to her chest.
"I love you," Cora said and Regina chose to ignore how manipulated it sounded because in this moment she had her mother.