Jeanette Peterson is the main antagonist of P.S. I Love You, Bad Crazy and Weekend at Barney's and Sunrise and makes a brief appearance in Gary Blauman (the 15th, 16th and 18th Season 8 episodes and the 17th and 21st Season 9 episodes of How I Met Your Mother respectively). A couple small clips of her from Sunrise is also used again with an additional shot in the 22nd Season 9 episode The End of the Aisle. She is a short-tempered cop who became fixated on Ted Mosby and stalked him for a year before starting a relationship with him and realizing more and more how mentally-ill Jeanette was prevented him from having to break up with her or incure her wrath.
She was portrayed by Abby Elliott, daughter of comedian Chris Elliott who played Hanson in Scary Movie 2.