Margaret Cochran was a lonely accountant who worked for Buchanan Enterprises. One day, Todd Manning (who was looking for dirt on Kevin) paid her a visit. He lured her with kind words for romance, only to get information. Believing that Todd was sincere, Margaret fell in love with Todd. Unfortunately, the feeling wasn't mutual, which caused Margaret's love to develop into obsession. After kidnapping the baby that Kelly Cramer had been raising to hold against Todd, Margaret was arrested.
The police couldn't hold Margaret back, however. She escaped just a few months later and had her mind set on what she wanted -- Todd. On the day of Todd's wedding to Blair, Margaret shot Todd in both of his legs and took him to a cabin that she had reserved in hopes of getting snowed in. She tied Todd's hands to the bed post, making sure that he couldn't escape. Margaret knew that she couldn't make Todd love her, but decided that she wanted a baby from him. After Margaret killed Mrs. Bigelow (Todd's assistant) after she'd discovered what had happened, and locking Blair in the trunk of a car, Todd finally gave in. Margaret raped him, in hopes of getting pregnant with his baby. The next day, she took a pregnancy test and was furious when it came up negative. Margaret was so mad that she left an explosive in the cabin and escaped. Luckily, Kevin arrived to save Todd. After Margaret was gone, she took another pregnancy test.
Months later, after things were finally getting back to normal for Todd and Blair, Margaret returned -- pregnant. At first, she was staying with Asa Buchanan. Asa invited Todd over, in hopes that he and Margaret would kill each other. After Margaret introduced "Little T.J." to his "daddy", Todd tried to strangle her. To protect herself, Margaret stabbed Todd with a pair of scissors. After this, Margaret found an apartment and used an alias everywhere she went. Todd discovered what her alias was and tracked her down. He nearly killed her once more, but Kevin came to stop him. This allowed Margaret to escape, where she lived on the streets. After her gun had run out of bullets, Margaret called her niece, Ginger Foley. She demanded money from Ginger and bought bullets and knitting material.
Soon, Margaret's "Fairy God Father" arrived -- Spencer Truman. He offered to help her get everything that she wanted. After Margaret tried to kill Todd's daughter, Starr, Todd was ready to kill Margaret. He lured her out of hiding with a personal ad dedicated to her. Spencer warned her that it could be a trap and gave her a plan, which Margaret obeyed. Although Margaret was a swimming champion, she told Todd that she couldn't swim. Todd rowed her out on a boat, ready to push her over. After the bodies of a woman and an infant were found in the lake, it was believed that Margaret and her child were dead, and Todd was eventually arrested with her murder and, after being convicted, received the death penalty.
It turned out that Margaret, deciding that Todd wouldn't push her over, Margaret threw herself off the board. She swam to safety and, with Spencer's help, faked her own death and lived in a warehouse until it was time to deliver her son. As Todd was being sentenced to death, Margaret went into labor. Spencer called in Paige to help him deliver the baby. Although Paige didn't want to keep the secret of Margaret being alive, Spencer forced her to. Later, Margaret realized that Spencer had his own agenda and he was only using her.
As John and Natalie were in Thailand looking for David Vickers, they also stumbled upon Margaret who was supposed to be dead. Margaret had absolutely no memory of her past with Todd Manning, the birth of her child, or her relationship with Spencer Truman. They brought her back to Llanview to stop Todd's execution but were too late. Once Spencer and his teach of doctors brought Todd back to life, Margaret agreed to undergo treatment to restore her memory. Margaret's memory was eventually fully restored but before she had the opportunity to speak with Bo, the van she was in crashed and she died.