She was following him, in the now blood-stained snow that seeped through his footprints. She didn't know what happened to him, but he had left his screwdriver several feet back, absentmindedly dropping it from the pain. Clara knew what happened next, but she didn't want it to. Being a Time Lady at one point when she had saved him from the Great Intelligence, she knew about regeneration.
Clara had been placed into the third generation of one of which she forgot the name. All she retained from that life was that she was born through regeneration, already full-grown, and had died from it. She remembered that she had fallen off of a balcony of her home, but it wasn't the fall that she had remembered, it was the golden light that surrounded her, which seemed comforting at the time, as if she knew what it was, but she didn't. She only had the memories of previous regenerations of the Time Lady, but not many. All she knew was that she was regenerating. The golden light around her grew stronger, and then she felt an extreme pain as the light engulfed her, and then she was no more.
Clara didn't want this to happen to the Doctor, not here, not now, not ever. She had seen all of his faces, all with different personalities, and she didn't want her Doctor to leave her with a different person. She was crying more than he was, but that was probably because he was fighting just to stay up, gripping the TARDIS console with all of his might. The golden light she had remembered began to shine from the Doctor, and she knew that it was starting for him. He stared at his hands in wonder, but at the same time in knowing, almost completely ignoring Clara. He had stopped bleeding and he looked fine from the outside, but Clara couldn't bear to witness the next part. The Doctor screamed at her to get back, but she didn't want to. She stood, frozen, as tears streamed down her face and the light was becoming stronger. Suddenly, she was thrown back from a shockwave of regeneration energy, leaving her on the cold floor beneath the TARDIS console, where the Doctor had spent much of his time tweaking and fixing its workings. She mustered the strength to look up, where blazes of light shot out from where the Doctor was, and then she began to lose consciousness as the energy died down.
She woke up in her room, aching everywhere; it was reminding her that what had happened wasn't a dream every time she moved. She wanted to stay under her soft blanket for the rest of her life, hiding from the universe, but she didn't. She slowly got up, and headed back out to the console room, silently wishing that her Doctor would be there to greet her. Instead she found a new man, patiently waiting to take her on the trip of a lifetime.