Those who survive
Jesse Ryan would rise to become one of the most top footballers in America eventually playing for the New England Patriots. But he never got over Rachel's death the woman who he loved and now feared. She was an enigma. For as long as he lived he kept one picture of her with him, at home and at work, later on as time and money allowed it he had several more made. After Rachel's death he took it upon himself to care for Rachel beloved Bassett Hound, Walter. Walter died of old age at 16. After a career in football he later went on to coach the next generation of the of Bates Bulldogs.
Jesse realises that she was responsible for the slaughter of all his friends and nearly killed him in the process but it did little to change his feelings for her she was the only woman he is ever loved deeply, and truly No matter how angry or hurt she was she couldn't bring herself to kill him. He knew it and she knew it.
Sometimes he wished he had been in that house earlier and protected his girl from Mark, Eric and the others but he would never know that it would have never made any difference, had that been the case they would have simply restrained him and forced him to watch as they taunted her*1.
Eleanor Snell, Sue's mother cursed the White sisters both of whom had brought so much untold suffering and misery on her family. The first Carrie White had taken away her daughters future and cost Sue her sanity. The second Rachel Lang had taken away her life. It felt as though her own family had been afflicted with some sort of curse, a telekinetic curse which came periodically to claim its victims, the curse of the White sisters.
Despite all this Eleanor later found it in her heart to forgive them. The last time she visited their grave she prayed that in death they would find along with Sue Snell the peace that they never found in this life. Eleanor Snell would never recover from Sue's death an according to her surviving daughter*2 died from a broken heart.
Sue's death marked the end of the last survivor who bore witness to Carry White's telekinetic ability if not the last survivor of the black prom. The next generation of Snells took it upon themselves to ensure that future tragedies like Carrie White and Rachel Lang would not happen. In the years to come one of their descendants would successfully map Carrie's White and Rachel Lang's family tree and science finally mapped the telekinesis gene.
*1fact acquired from the script
*2 in Brian Palma's Carrie the entire Snell family is seen at dinner. Sue Snell may also have a brother named Bobby.