A friend of Ouzounian's tells PEOPLE the ex-nanny told friends the affair "has been going on for a long time;" adding, "Christine is in love with him." (PEOPLE has not been able to reach Ouzounian for comment.)
Affleck denies any affair, with his rep denouncing a report as "complete garbage and full of lies." A source close to Affleck says he and Ouzounian had "a work relationship and a friendship. There has never been a romantic or sexual relationship."
But just who is the woman now at the center of the scandal? Here are five things to know about Ouzounian.
1. She's a California native who likes to have "fun"
She might not be as famous as the people she's worked for, but she knows the Southern California terrain just as well. The 28-year-old grew up in Santa Monica, home to numerous celebrities. She also spent time in Arizona while attending Arizona State University. A friend of Ouzounian's tells PEOPLE her pal embodies the image of a California girl: "She's very well put-together and fun."
2. She once worked for Neil Patrick Harris
Garner and Affleck were not her first celebrity clients. Ouzounian once cared for Neil Patrick Harris and David Burtka's twins, 4 ½. According to a now-deactivated LinkenIn profile, her previous jobs included teacher at a Head Start Academy, concierge at Four Seasons Hotels and Resorts, and sales intern at Prudential California Real Estate.
3. She has a twin sister who also works with celebrities
Christine's sister Caty lists herself as a house manager and personal assistant on LinkedIn, whose clients include Harris and Burtka and former Spice Girl Melanie Brown. "I have a calm and demure demeanor, which aids in my ability to anticipate the unknown for my employer," Caty Ouzounian writes in her summary. "I'm socially appropriate and understand the fine lines involved when working in someone's home."
4. She spent time living in the Bahamas
Garner and Affleck were on vacation in the Bahamas when news of their split went public, and turns out the vacation spot is an area Ouzounian knows well. According to a friend's wedding website on TheKnot, Ouzounian once lived in the tropical paradise.
5. She was only employed by Affleck and Garner for a short time
Affleck and Garner found Ouzounian through a high-end Beverly Hills nanny service earlier this year. She began working for them in the spring, caring for children Violet, 9, Seraphina, 6, and Samuel, 3, and was with the couple in the Bahamas earlier this month when they announced their split. She is no longer an employee of the family.