|“||Sam, is it really you? (puts hand on Sam's chest) And you're so firm!||”|
Her online name was samlicker81, and she was the webmistress of morethanbrothers.net. Carver Edlund aka Chuck Shurley contacted her and enlisted her to get a message to Sam and Dean Winchester. At first, she believed it was a prank before he told her that everything in the books was real which delighted her as she thought it was. Becky then went off to meet the Winchesters, after finding them she was greatly excited. It was obvious from her reaction upon meeting the boys that she was a Sam Girl, due to being more interested in him than Dean. She then gave them Chuck's message though it was rather complex for them to understand.
She later used Chuck's phone and tricked the boys into going to the "first ever" Supernatural convention in The Real Ghostbusters. When Sam managed to recall her name, she blurted out that she couldn't stop thinking about him, either. While there, she continued to flirt with Sam (who wasn't flirting back) so she was initially oblivious to Chuck's crush on her. Only when Chuck saved the hotel manager did she notice him and want to be with him. So, she proceeded to 'break up' with Sam gently, believing that she had hurt him. He played along, which made her happy. It was Becky who revealed to Sam where the Colt was, because she'd read the book. She told Sam that Bela gave The Colt to a demon named Crowley.
Sometime later she and Chuck broke up, with Becky thinking she may have intimidated him with her sexual drive.
She appeared again in Season Seven, Time for a Wedding! when she used a potion to drug Sam. While drugged, Sam married her, making her wildest dreams come true. With Sam as her husband, she quickly headed over to RSVP to her high school reunion to show off. On the way out she bumped into Guy, who gave her more potion. She and Sam went back to her parents' cabin and began working on a case together. When the potion started to wear off, she knocked Sam out and tied him up until she could get more from Guy.
She was horrified to learn that he was a crossroad demon and not a Wiccan as she thought. Guy offered her a 25-year deal, but Sam convinced her not to take it and to help them defeat Guy. She teamed up with the Winchesters and Garth to stop Guy by pretending to take the deal, and then tricked him into a devil's trap.
Becky was excited that the ruse worked at first, but upon getting a look from Sam and Dean, slinked off to watch from a safe distance. Guy revealed he had a demon "intern" named Jackson committing murders to call in his deals early. Jackson appeared, attacking Dean and Sam who told Becky to run when the fighting started, which she did only long enough to grab the demon-killing knife and stab Jackson in the back, killing him to her amazement. Her quick action saved Sam and allowed Dean to overpower Guy after Sam tossed him the knife. As the Winchesters tried to force Guy to break his deals, Crowley appeared. Becky excitedly recognized him, to his bemusement. Crowley, extremely annoyed by Guy's deal-making antics, decided to make an example of him, and to nullify all 15 of his recent deals. Sam later obtained an annulment from Becky, but as she saved his life, grudgingly told her that she was a good person, and encouraged her to find someone who loves her for her. She and Garth then made eye-contact that lingered, which Dean noticed and immediately shut down.
In Slumber Party, Charlie referred to a person on the internet publishing the Supernatural books on-line. The said person had the username 'BeckyWinchester176' that most likely referred to Becky Rosen. Sam quickly denied any knowledge of who it was but was clearly uncomfortable.
In Various & Sundry Villains, Sam realizes that Dean might be under a love spell and reminds him of the incident with Becky in Las Vegas as an example. Unfortunately, Dean did not remember the incident, nor Becky, anymore.
In Atomic Monsters, Becky is revealed to have gotten married and has two kids. She is getting her family ready for a trip to have some alone time. After they leave, she spots Chuck Shurley and the latter begs for help. However Becky tells him to leave because of how she is moving on with her life and has realized what she did to Sam was wrong. After Chuck pleas to her, she reluctantly lets him in her home. They catch up with him revealing his falling out with the Winchesters and his sister. Becky describes her own life with a family and selling supernatural merchandise, that she's doing pretty well for herself. After Chuck reveals that he has had writers block, she helps him get over it and he creates a draft of a story. Becky tries to hide criticisms of it but this motivates Chuck to go deeper into his writing. Reading it, Becky is horrified and tries to talk him out of the ending but Chuck is insistent, describing it is the perfect way to end the story. Becky then hears her husband arrive and tells Chuck to leave but he refuses. With a wave of his hand Chuck causes Rod to disappear and Becky is horrified by this display, especially when he reveals that he is actually God. When her kids approach, God causes them to disappear as well but reassured her that they are alive. Becky begs him to bring them back, though her pleas are ignored and he erases her from existence with a snap of his fingers, stating he can do whatever he wants because he's a writer. God then takes Becky's house as his new residence to write.
Becky is a very excitable and obsessed woman, as seen when she is introduced and told Chuck Shurley about her activities in his book. She was this way after meeting Sam Winchester in person and frequently touching him, despite him asking her to stop.
She is very open minded, as after being informed all the things in her favorite books were real she was excited and stated she knew they were real, despite just saying it was fiction. When meeting the Winchesters again, she was excited to be a part of their adventures and to witness them speaking at the same time like in the books.
Her knowledge of the books has helped her, as she was able to tell Sam important info on The Colt, identify a crossroads demon after he revealed himself, and successfully used a Devil's Trap. Becky was even knowledgeable in using Demon-Killing Knife to save Sam. Becky even excitedly deduced the identity of Crowley in their meeting.
Deep down, she is very self-conscious as seen when she lamented being a loser in school and life. She truly yearns to be loved, being sad at being dumped by Chuck Shurley but she took drastic measures to ensure it as seen when slipping Sam a love potion. In the end, Becky has a good heart as she refused to sell her soul for love and freed Sam to stop Guy from doing anymore harm while even saving Sam from a demon.
In time after her adventures, she has got help for her issues and became more adjusted. She has become more happy with a family life, as she was horrified to watch her husband and kids disappear. She shows that she feels guilt over what she did to Sam after realizing she was not in love with him. When meeting Chuck again, she voiced her resentment at him for dumping her but helped him with his writers block. However, she was shocked to learn he was actually God and to learn the ending he had planned for Sam and Dean, as well as him banishing her family.