In the story
After accidentally shooting herself in the head, Paulson survived with a bullet lodged in her brain. Soon after, she became convinced that a picture of Jesus was talking to her, revealing her husband's infidelities, and explaining how to rig her television set in order to electrocute him. She did so, and tricked her husband into touching the power knob on the television, but as he was electrocuted, she realized what she had done.
Trying to save her husband, Becka was killed as well.
In the novel
Outside of the original short story, Rebecca Paulson's first appearence was in It where she is mentioned as finding some of the money that had been scattered throughout Derry and Haven after the destruction of a bank in Derry during the chaos that coincided with It's destruction.
In the miniseries
Paulson was portrayed by Allyce Beasley.
Rather than attempting to rescue her husband from electrocution, Becka mourned her actions, and was eventually incarcerated in a mental hospital.
In the episode
Paulson was portrayed by Catherine O'Hara.
Rather than being addressed by a picture of Jesus, Becka became convinced that a man on her television set was talking to her.