Jefferson woke her
A guest asked for a oneshot of Snow waking up when Jefferson kidnaps her and Emma in season 1 because she sees Emma in danger.
It was like the embers had been glowing inside of Mary Margaret for twenty-eight long years. Just waiting for the right spark to come along and ignite a fire that brought about her phoenix-like transformation back into her true self. That spark came in the form of seeing the Mad Hatter holding a gun to her daughter's head. Suddenly, she was no longer timid little Mary Margaret the school teacher. She remembered. She was Snow White. Queen. Warrior. Wife. Mother. Jefferson wasn't threatening her new-found best friend; he was threatening her daughter. There was no way in Hell she was letting that happen.
"NO!" Snow bellowed. Jefferson turned and watch her struggle harder against the bonds of her chair. He gave a manic laugh.
"Well would you look who's awake?" Jefferson said. "I don't think it's Mary Margaret in that chair anymore, is it?"
"You're damn right it's not, now if you want to fight someone, you fight me." Snow snarled. Emma blinked, very confused. That didn't sound at all like Mary Margaret.
"What's going on?" She asked.
"Emma, get away from Jefferson." Snow ordered her. "He's crazy."
"Oh, I'm not crazy. I'm mad." Jefferson corrected her. "But the mad man still has the gun, so precious little Emma is coming with me."
"No!" Snow repeated. By this point, she'd managed to untie the knots at her hands. She'd had enough experience with boobytraps to know how to undo some knots. Before Jefferson could stop her, Snow also ripped the knots off her ankles and came charging towards him. Within a few moments she had the gun knocked out of his hand. Jefferson turned angry quickly.
"I need her to fix everything!"
"I don't care what you need Emma for. You're not putting her in danger!" Snow yelled. Emma came over and helped her wrestle Jefferson into the chair and tied him up. They covered his mouth with the gag to stop his incessant babbling.
"What's going on?" Emma asked again. "What did he mean it wasn't you tied in the chair anymore?" Snow smiled and pressed her hand against Emma's cheek, her daughter's cheek. Emma felt uncomfortable. This wasn't like Mary Margaret.
"He woke me up." Snow responded. "Emma, Henry's been right all along. About the curse, about everything. I know it's a lot to take in, but he's right. I am your mother. I am Snow White." Snow promised her. Emma took a step backwards.
"Did Jefferson hit you in the head before I got here?" Emma asked. "Because I should take you back to the cell before Regina arrives in the morning, but if you're badly hurt maybe you need to go to the hospital…" Snow shook her head. She knew the chances were Emma wouldn't believe her. She hadn't believed Henry all this time.
"I haven't banged my head. I haven't been drugged. I have just woke up. The curse is real, Emma. You're going to break it soon and you'll see. Then you'll wake your dad up and we'll be together again. What about you, did Jefferson hurt you?" Snow asked, concerned. Emma shook her head. She couldn't speak right now. There were too many thoughts whirling round her head. "Good. Then we go back to the cell. If Regina finds me not there then she'll have me taken over the town line and I don't want to know what happens if I try to leave. Come on, lets go." Snow said, guiding Emma with a gentle hand on her back. Emma looked back at Jefferson, still tied to the chair, then to her roommate. Surely this couldn't be true, could it? They were the same age. No, it was impossible. She must have hurt her head and not remembered. This curse could not be real.
