She meets Sheldon personally in a cafeteria and arranges to have dinner with him in his apartment. Where other people might be worried about such behavior being reminiscent of stalking, Sheldon reacts positively to Ramona by appreciating the fact that he's getting a free dinner. During their date, the rest of the gang is sitting on the couch as spectators of this strange turn of events.
She keeps "helping" Sheldon by arranging suitable working conditions for him, such as getting breakfast for him at the cafeteria and giving him foot rubs. Unfortunately for Sheldon, she overdoes her insistence that Sheldon dedicate his time solely for work, depriving him of his favorite hobbies such as playing games, watching TV, and going for paintball with the guys. Even more unfortunately for Sheldon, he can't seem to get rid of her, especially when she settles herself in his apartment. At times, she appears very suddenly and stalks around the apartment staring at people like the T-X from Terminator 3: Rise of the Machines.
Ramona proves to be irritating for the entire group, especially when she assumes that Penny likes Sheldon. She still asks Penny to be sisters with her. She makes it difficult for anyone to communicate with him and scares them away.
When Sheldon makes a scientific breakthrough with his work, Ramona suggests they share credit, where Sheldon finally gets the nerve to tell her to "Get out". Ramona stormed out of the apartment and went back to her own place. After that, she wasn't seen again for the rest of the series.
However, she reappears in the Season 10 finale, "The Long Distance Dissonance", when Sheldon's new love interest, Amy Farrah Fowler, has gone to Princeton for a 3-month internship, and it becomes apparent she hasn't changed very much since her last appearance. Penny, Bernadette, and the others become concerned for Sheldon, and try to put some distance between him and Ramona. Sheldon repeatedly tries to tell her that he already has a girlfriend, Amy, but that doesn't convince her to back off. Eventually, her pushiness leads Sheldon to fly to Princeton and propose to Amy.