Disclaimer – if you recognise it then it belongs to GRRM
The pain was excruciating, worse than she had ever expected. Not that she had paid much attention to her Septa when she was growing up as she whittled on and on about what a lady should expect to be, do and feel. Lyanna didn't like the idea of her innermost feelings being dictated for her – she was her own woman and she would feel whatever she actually did when and if it happened. Besides she was more than often distracted by watching Brandon sparring out the window with one of his friends or a visiting Lord.
She missed her big brother and wished he was here now. The pain of giving birth was nothing compared to the pain she felt in her soul when she heard of the death of Brandon. She had wept for days and even the love of her Dragon Prince could not end her suffering. It was only when she learned she was pregnant with Rhaegar's child that she managed to smile again. And now he was gone too, killed by Robert in the flowing waters of the Trident.
She felt such guilt at the lives that had been lost by this wild passion between her and Rhaegar. Even now men were fighting Gerold, Arthur and Oswell beneath her window, all because she and Rhaegar were unable to be apart and stick to their duties. It occurred to Lyanna that this pain was maybe her punishment from the Old Gods for her recklessness and the many deaths caused because of it.
She was trying to focus on the fighting outside the window to distract herself from the birth. She could hear that Gerold and his men were outnumbered by the voices but she was still confident in their abilities. She had grown close to the three kingsguard that had stayed here with her, especially Arthur with his warm smile and dry wit, and she hoped that they would all survive this fight with the men that Robert had sent to retrieve her. Lyanna knew Robert would kill her child in a heartbeat so she had to pray that her kingsguard survived.
The pain increased dramatically and Lyanna cried out in pain. The bed was now covered in blood and Lyanna felt dizzy. She knew that something wasn't right and surely there should not be this much agony in childbirth. She continued to push hard, gripping the sheets tightly in her hands and screaming in pain at the top of her voice. The child finally managed to be born, releasing a mighty cry of arrival, just as all the noise from below her window ended. Lyanna smiled with relief and lay back flat on the bed, too tired to lift herself to hold the baby. The pain had not subsided and coursed through her body in waves, from her fingers right down to her toes.
She heard footsteps coming up the stairs towards her chambers. In panic she tried to raise herself but the pain was too much. She tried to push the bedding over the baby with her feet but could only manage to cover its legs. The door swung open and there was Arthur. He held Dawn in his hand and the pale blade was coated with dark red blood. The white of his Kingsguard armour was also splattered with red blood, though none of it appeared to be his own. He scanned round the room quickly. "Lyanna are you alone?" he asked briskly.
She nodded tiredly. Seemingly satisfied with her response he moved to the bed. He saw the baby and smiled "You have a son Lyanna."
"Is he healthy?" she asked softly, her strength failing.
"I am no septa but he looks good to me." Arthur replied. He noticed the boy was still attached to his mother via the cord so he lightly cut it using Dawn before sheathing the blade. Next he removed his white cloak and blanketed the baby, picking it up so Lyanna could finally see her son. Despite the pain in her body she smiled brightly at the young boy. He had dark hair and grey eyes – the Stark colouring. He was amazing to her and she knew Rhaegar would have felt the same as well.
But she knew she was dying so she could not waste time, even if she wanted to more than anything in the world. "Listen Arthur I am not long for this world. You must take my son to Winterfell where Ned will care for him. He does not look like a Targaryen so he will be safe there."
Arthur looked pensive and finally replied "Lyanna, I'm sorry but your brother Ned is dead."
Lyanna was confused until Arthur motioned out the window with his head and it became clear to her.
"He was one of the men who came here today?!" She asked. She wanted to cry though no tears were left in her body.
Arthur replied with sadness in his voice. "Yes. He came with six others. Eventually there was only me and him left, then there was only me. He was good but I was the better sword today."
"You did not have to kill him Arthur, he would never have harmed me or the baby."
"Maybe he wouldn't but even he could not have stopped the Usurper who certainly would. Anyway I made a vow to Rhaegar."
Lyanna coughed which felt agonising in her body. The room started to darken. "Now you must make a vow to me Arthur. You must swear to protect my son and keep him safe for as long as you can. Promise me Arthur, promise me."
Arthur looked her directly in the eye. "I swear Lyanna."
She felt light as a feather and the pain was easing away. She began to close her eyes, for what she knew was to be the final time. "Jon," she spoke quietly with the last of her breath, "his name is Jon."